英語イディオム100選：意味と例文で覚える必須リスト
文法が完璧で語彙が10,000語あっても、ネイティブとの会話で3文に1文の意味がわからない — そんな経験はありませんか？その原因はイディオムです。ネイティブスピーカーはイディオムを常に、無意識に、自動的に使っています。
これが必須リストです。英語学習者が知っておくべきイディオム100選。珍しい文学表現や古風な言い回しではありません。映画、会議、ポッドキャスト、ニュース、日常会話で実際に耳にするイディオムです。それぞれに明確な意味と自然な例文を付けています。
- 収録数: 100イディオム
- 形式: イディオム → 意味 → 例文
- 整理方法: 10のトピック
- レベル: B1〜C1
500以上のイディオムの完全コレクションは 英語イディオム：500以上の頻出表現 をご覧ください。イディオムの仕組みの詳しい解説は 英語の慣用表現：イディオムの完全ガイド をご覧ください。
日常の場面
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 1 | a piece of cake | とても簡単なこと | The exam was a piece of cake — I finished in 20 minutes. |
| 2 | break the ice | 気まずい場で会話のきっかけを作る | He told a joke to break the ice at the meeting. |
| 3 | call it a day | その日の仕事を終える | We’ve been at this for hours — let’s call it a day. |
| 4 | get out of hand | 手に負えなくなる、制御不能になる | The argument got out of hand and people started shouting. |
| 5 | no-brainer | 非常に簡単な決断 | Accepting the scholarship was a no-brainer. |
| 6 | on the same page | 意見が一致している、同じ認識を持っている | Before we continue, let’s make sure we’re all on the same page. |
| 7 | at the end of the day | 結局のところ、最終的には | At the end of the day, what matters is your health. |
| 8 | give it a shot | 試してみる | I’ve never painted before, but I’ll give it a shot. |
| 9 | under the weather | 体調が悪い、気分が優れない | I’m feeling a bit under the weather — I think I caught a cold. |
| 10 | the last straw | 我慢の限界、最後の一押し | His constant lateness was the last straw — she fired him. |
成功・失敗・努力
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 11 | hit the nail on the head | 的を射た発言をする | You hit the nail on the head — that’s exactly the problem. |
| 12 | back to square one | 最初からやり直し | The project failed, so we’re back to square one. |
| 13 | go the extra mile | 期待以上の努力をする | She always goes the extra mile for her customers. |
| 14 | miss the boat | チャンスを逃す | If you don’t apply by Friday, you’ll miss the boat. |
| 15 | cut corners | 手抜きをする、いい加減にやる | They cut corners on the building and now the roof leaks. |
| 16 | the ball is in your court | あなたの番だ、次はあなたが動く番 | I’ve made my offer — the ball is in your court. |
| 17 | learn the ropes | 仕事や作業のやり方を覚える | It took me a month to learn the ropes at my new job. |
| 18 | throw in the towel | 諦める、ギブアップする | After five failed attempts, she threw in the towel. |
| 19 | burn the midnight oil | 夜遅くまで働く、徹夜する | Students burn the midnight oil before final exams. |
| 20 | ahead of the curve | 他より先を行っている、進歩的 | Their company is always ahead of the curve with technology. |
お金とビジネス
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 21 | cost an arm and a leg | 非常に高い | The car repair cost an arm and a leg. |
| 22 | break the bank | 予算を超える、手が出ないほど高い | A weekend trip doesn’t have to break the bank. |
| 23 | make ends meet | 収支をやりくりする、生活をやりくりする | It’s tough to make ends meet on a single income. |
| 24 | get the ball rolling | 物事を始める、スタートを切る | Let’s get the ball rolling on this project. |
| 25 | think outside the box | 型にはまらず発想する | We need to think outside the box to solve this problem. |
| 26 | bring to the table | 貢献する、提供する | What experience do you bring to the table? |
| 27 | the bottom line | 結論、最も重要な事実 | The bottom line is that we need to increase sales by 20%. |
| 28 | in the red | 赤字、損失状態 | The company has been in the red for three consecutive quarters. |
| 29 | a ballpark figure | おおよその見積もり | Can you give me a ballpark figure for the renovation cost? |
| 30 | put all your eggs in one basket | 一つのことに全てを賭ける | Don’t put all your eggs in one basket — diversify your investments. |
感情と気持ち
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 31 | on cloud nine | 非常に幸せ、有頂天 | She’s been on cloud nine since she got the promotion. |
| 32 | over the moon | 大喜びしている | They were over the moon when they heard about the baby. |
| 33 | down in the dumps | 落ち込んでいる、憂鬱 | He’s been down in the dumps ever since the breakup. |
| 34 | butterflies in my stomach | 緊張で胸がざわざわする | I always get butterflies in my stomach before a presentation. |
| 35 | blow off steam | ストレスや怒りを発散する | After a stressful day, I go for a run to blow off steam. |
| 36 | keep a stiff upper lip | 冷静さを保つ、感情を表に出さない | Despite the bad news, she kept a stiff upper lip. |
| 37 | lose your cool | 怒ったり動揺したりする | Try not to lose your cool during the negotiation. |
| 38 | get cold feet | 不安になってためらう | He got cold feet the night before the wedding. |
| 39 | have a heart of gold | 非常に親切で寛大な人である | She has a heart of gold — she volunteers every weekend. |
| 40 | sick and tired | うんざりしている、完全にイライラしている | I’m sick and tired of hearing the same excuses. |
コミュニケーション
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 41 | beat around the bush | 本題を避けて回りくどく話す | Stop beating around the bush and tell me what happened. |
| 42 | spill the beans | 秘密を漏らす | Someone spilled the beans about the surprise party. |
| 43 | get straight to the point | 率直に本題に入る | I’ll get straight to the point — we’re cutting the budget. |
| 44 | speak your mind | 本音をはっきり言う | She’s never afraid to speak her mind in meetings. |
| 45 | read between the lines | 行間を読む、隠された意味を理解する | If you read between the lines, it’s clear he’s unhappy. |
| 46 | keep someone in the loop | 情報を共有し続ける | Please keep me in the loop on any changes. |
| 47 | ring a bell | どこかで聞いたことがある、思い出す | The name rings a bell, but I can’t remember where I heard it. |
| 48 | word of mouth | 口コミ、人づてに広まる情報 | The restaurant became famous through word of mouth. |
| 49 | take with a grain of salt | 鵜呑みにしない、半信半疑で受け取る | Take online reviews with a grain of salt. |
| 50 | cut to the chase | 本題に入る、要点に入る | Let’s cut to the chase — what’s your offer? |
人間関係
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 51 | see eye to eye | 完全に同意する | We don’t always see eye to eye on politics, but we respect each other. |
| 52 | stab someone in the back | 信頼している人を裏切る | He stabbed his partner in the back by stealing the idea. |
| 53 | give someone the cold shoulder | 意図的に無視する | After the argument, she gave him the cold shoulder for a week. |
| 54 | bend over backwards | 全力で助けようとする | The hotel staff bent over backwards to make our stay perfect. |
| 55 | bury the hatchet | 争いを終わらせて和解する | It’s time to bury the hatchet and move forward. |
| 56 | hit it off | すぐに仲良くなる | We hit it off at the conference and became business partners. |
| 57 | two-faced | 二面性がある、裏表がある | Don’t trust her — she’s completely two-faced. |
| 58 | give someone the benefit of the doubt | 疑いを持たず信じてみる | I’ll give him the benefit of the doubt this time. |
| 59 | go behind someone’s back | こっそり裏で行動する | She went behind my back and complained to the manager. |
| 60 | thick as thieves | 非常に仲が良い、いつも一緒 | Those two have been thick as thieves since childhood. |
時間
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 61 | in the nick of time | ぎりぎり間に合う | The ambulance arrived in the nick of time. |
| 62 | once in a blue moon | めったにない、滅多にない | I only go to the cinema once in a blue moon now. |
| 63 | around the clock | 24時間休みなく | The hospital operates around the clock. |
| 64 | at the eleventh hour | 土壇場で、最後の瞬間に | The deal was saved at the eleventh hour. |
| 65 | time flies | 時間が経つのは早い | Time flies when you’re having fun. |
| 66 | kill time | 時間をつぶす | I killed time at the airport by reading a book. |
| 67 | behind the times | 時代遅れの、古い | His teaching methods are behind the times. |
| 68 | against the clock | 時間との戦い、急いでいる | We’re working against the clock to finish before the deadline. |
| 69 | better late than never | 遅くてもしないよりはマシ | You finally submitted the report — better late than never. |
| 70 | stand the test of time | 長い間有効である、時代に耐える | Their friendship has stood the test of time. |
知識と学習
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 71 | learn the hard way | 苦い経験から学ぶ | He learned the hard way not to skip backup copies. |
| 72 | a steep learning curve | 最初は習得が難しいこと | There’s a steep learning curve with this software. |
| 73 | know something inside out | 徹底的に知っている | She knows the tax code inside out. |
| 74 | pick someone’s brain | 意見や情報を聞く | Can I pick your brain about the marketing strategy? |
| 75 | food for thought | 考えるべきこと、示唆に富むこと | Your proposal gave us a lot of food for thought. |
| 76 | in a nutshell | 要するに、簡潔に言うと | In a nutshell, we need more funding and more time. |
| 77 | get the hang of it | コツを掴む、やり方を覚える | The software is confusing at first, but you’ll get the hang of it. |
| 78 | scratch the surface | 表面だけ触れる、ほんの一部に過ぎない | We’ve only scratched the surface of this topic. |
| 79 | the tip of the iceberg | 氷山の一角、見えている部分はほんの一部 | The complaints we’ve received are just the tip of the iceberg. |
| 80 | a quick study | 物覚えが早い人 | She’s a quick study — she mastered the software in two days. |
問題と困難
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 81 | between a rock and a hard place | 板挟み、どちらを選んでも困る状況 | He’s between a rock and a hard place — resign or accept the demotion. |
| 82 | the elephant in the room | 誰も話したがらない明白な問題 | The company’s debt is the elephant in the room. |
| 83 | a blessing in disguise | 不幸中の幸い、一見悪いことが実は良い結果に | Losing that job was a blessing in disguise — I found a better one. |
| 84 | add fuel to the fire | 火に油を注ぐ、状況を悪化させる | His sarcastic comment only added fuel to the fire. |
| 85 | a can of worms | 厄介な問題、複雑な状況 | Asking about the budget opened a whole can of worms. |
| 86 | nip it in the bud | 芽を摘む、問題を初期段階で止める | Address the issue now before it grows — nip it in the bud. |
| 87 | turn a blind eye | 見て見ぬふりをする | The manager turned a blind eye to the safety violations. |
| 88 | weather the storm | 困難な時期を乗り切る | The company managed to weather the storm during the recession. |
| 89 | at the end of your rope | 限界、我慢の限界 | After months of problems, I’m at the end of my rope. |
| 90 | up the creek without a paddle | 困った状況で打つ手がない | If the funding falls through, we’re up the creek without a paddle. |
行動と決断
| # | イディオム | 意味 | 例文 |
|---|---|---|---|
| 91 | bite the bullet | 困難を覚悟して受け入れる | I bit the bullet and scheduled the dentist appointment. |
| 92 | pull someone’s leg | 冗談を言う、からかう | I’m just pulling your leg — of course I didn’t sell the car. |
| 93 | let the cat out of the bag | うっかり秘密を漏らす | Who let the cat out of the bag about the merger? |
| 94 | play it by ear | 臨機応変に対応する | We don’t have a detailed plan — let’s play it by ear. |
| 95 | sit on the fence | 決断を先延ばしにする、どちらにも決めない | Stop sitting on the fence and choose a side. |
| 96 | bite off more than you can chew | 手に負えないほど引き受ける | I bit off more than I could chew by agreeing to three projects at once. |
| 97 | cross that bridge when you come to it | その時になって対処する | Don’t worry about it now — we’ll cross that bridge when we come to it. |
| 98 | leave no stone unturned | あらゆる手段を尽くす | The investigators left no stone unturned in the search. |
| 99 | jump on the bandwagon | 流行に乗る | Every company is jumping on the AI bandwagon. |
| 100 | sleep on it | 一晩考えてから決める | That’s a big commitment — why don’t you sleep on it? |
この100イディオムの覚え方
ステップ1: 100個を一度に暗記しない。 1週間に1トピック（10イディオム）を選び、その週は映画、ポッドキャスト、記事の中でそれらのイディオムに出会うことに集中しましょう。
ステップ2: 自分の文を書く。 各イディオムについて、自分の生活に関する2〜3文を書きましょう。”I got butterflies in my stomach before my driving test”は記憶に残ります。一般的な例文は残りません。
ステップ3: 実際の英語でイディオムに気づく。 意識し始めると、これらのイディオムはどこにでも現れます — TV番組、ニュースの見出し、SNS、会話の中で。自然な出会いのたびに記憶が強化されます。
ステップ4: 間隔反復を使う。 これらのイディオムをLinglifyの語彙に追加し、最適な間隔で自動復習しましょう。
ステップ5: 能動的に使う。 最も安全で普遍的なイディオムから始めましょう：at the end of the day, get the ball rolling, on the same page, in a nutshell。メール、会話、ライティングで使ってみてください。
練習用の単語
boom
名詞
急増, ブーム, 爆発
例
- The boom of thunder echoed across the valley.
- The technology boom created many new millionaires.
cooperate
動詞
協力する, 協働する
evaluate
動詞
評価する, 査定する
例
- Companies evaluate job candidates based on experience, skills, and personality.
- Teachers evaluate student progress through tests, projects, and classroom participation.
graduate
動詞
卒業する
例
- She will graduate from university next year with a degree in engineering.
- Students must complete all requirements before they can graduate from high school.
horizon
名詞
地平線
例
- The sun disappeared behind the horizon as evening approached.
- Traveling broadens your horizon and exposes you to new cultures.
indispensable
形容詞
不可欠な
例
- Clean water is indispensable for human survival and good health.
- Her experience and skills make her indispensable to the research team.
jury
名詞
陪審団, 陪審
例
- The jury deliberated for several hours before reaching a verdict.
- The talent show jury consisted of professional musicians and entertainers.
lifelong
形容詞
一生の, 生涯の
例
- Learning is a lifelong process that never truly ends.
- Their lifelong friendship began during elementary school years.
motivated
形容詞
やる気のある
例
- Motivated employee seeks additional responsibilities and challenges at work.
- Success requires being motivated even when facing difficult obstacles.
normally
副詞
通常は, 普通は, ふつうは
例
- Heart normally beats between sixty and hundred times per minute.
- Students normally arrive at school before morning bell rings.
off
副詞
離れて, 切れて, 休みの
例
- Please turn off the lights before leaving the room.
- The dog ran off into the forest chasing wild rabbits.
prejudice
名詞
偏見, 先入観, 差別
例
- Education helps overcome prejudice and promotes understanding.
- Racial prejudice damages communities and individuals alike.
resolve
動詞
解決する, 決意する
例
- Mediator helps parties resolve dispute through negotiation.
- Technical team will resolve software problems quickly.
stress
動詞
強調する, 緊張させる
例
- Heavy workload may stress employees beyond limits.
- Teacher will stress importance of homework completion.
total
形容詞
全体の, 総合的な, 完全な
例
- Total cost includes all fees and expenses.
- Total silence fills room during meditation session.
tragedy
名詞
悲劇
例
- Natural tragedy affects thousands of innocent people.
- Personal tragedy changes person's life perspective completely.
union
名詞
連合, 結合, 協会
例
- Labor union protects worker rights and interests.
- Marriage union joins two people in partnership.
voyage
名詞
航海, 旅行
例
- Space exploration represents humanity's greatest voyage into the unknown.
- The ocean voyage from Europe to America took several weeks in the past.
candidate
名詞
候補者, 志願者
例
- Each presidential candidate presented their policy plans to voters.
- The job candidate impressed the interview panel with her experience.
discourage
動詞
落胆させる, 思いとどまらせる, 意欲をなくさせる
例
- Don't let one failure discourage you from pursuing your dreams.
- High prices discourage many people from buying organic food products.
donate
動詞
寄付する
例
- Many people donate money to charities that help homeless individuals.
- She decided to donate blood to help patients in emergency situations.
firmly
副詞
しっかりと, 堅く
例
- Hold the rope firmly while climbing down the steep mountain slope.
- The manager firmly believed in treating all employees with respect.
guide
動詞
案内する
例
- Parents should guide their children to make responsible decisions.
- The experienced hiker will guide the group through the mountain trail safely.
humorous
形容詞
ユーモラスな, 面白い, 滑稽な
例
- She writes humorous articles about everyday life and family experiences.
- The humorous speech made everyone laugh and lightened the serious mood.
admission
名詞
入場, 入学, 認めること
例
- Her admission to the prestigious medical school was the result of hard work.
- The museum offers free admission on the first Sunday of every month.
よくある質問
最もよく使われるイディオム10選は？
話し言葉と書き言葉での頻度に基づくと：at the end of the day, a piece of cake, break the ice, on the same page, time flies, in a nutshell, the bottom line, get the ball rolling, cost an arm and a leg, bite the bullet。これらはビジネス、学術、カジュアルな会話のほぼすべての場面で安全に使えます。
イディオムとことわざの違いは？
イディオムは、個々の単語の意味とは異なる意味を持つフレーズです（”spill the beans” = 秘密を漏らす）。ことわざは、一般的な真理を表す完全な文です（”Don’t put all your eggs in one basket” = 一つのことに全てを賭けるな）。ことわざは助言を与え、イディオムは状況を描写します。多くのことわざも慣用的であり、実際には境界は曖昧です。
IELTSスピーキングでイディオムを使える？
はい — 使うべきです。IELTSスピーキングテストで2〜3個の自然なイディオムを使うことは語彙の幅を示し、スコアアップにつながります。一般的で広く理解されているイディオム（”at the end of the day,” “a piece of cake”）を使いましょう。無理やり使ったり間違えたりするとスコアが下がります。IELTS特化のイディオムは IELTSスピーキングで使えるイディオム をご覧ください。
100イディオムを覚えるのにどれくらいかかる？
1週間10イディオムのペースで毎日復習すれば、約10週間で全100個を学習できます。ただし「学習」とは能動的な使用 — 自分の文で自然にイディオムを使えることであり、単に認識できることではありません。認識には2〜3回の接触、生成には8〜10回必要です。間隔反復を使えばプロセスは大幅に加速します。
イギリス英語とアメリカ英語でイディオムは同じ？
最も一般的なイディオムの多くはイギリス英語とアメリカ英語で共通です。ただし、一方に特有のものもあります：”Bob’s your uncle”（イギリス）、”hit a home run”（アメリカ）。イギリス特有の表現は イギリス英語スラング200選 をご覧ください。このリストの100イディオムは両方のバリエティで普遍的に理解されます。
