1. to be slowly destroyed by natural processes
（因自然過程）腐爛，腐朽
The fallen leaves began to decay on the forest floor.
落葉開始在森林地面上腐爛。
If you don't brush your teeth, they will decay.
如果你不刷牙，牙齒就會蛀壞。
Decay Meaning（定義、用法、例句與發音）
decay
verb
快速理解
What does "Decay" mean?What are 2-3 core uses of "Decay"?
指物質因時間或自然作用而腐壞、分解，或抽象事物逐漸衰退、惡化的過程。
- 1
物理腐壞
EN: to rot or decompose
翻譯: （有機物）腐爛、分解
- 2
結構衰敗
EN: to fall into ruin or disrepair
翻譯: （建築、結構）破敗、失修
- 3
逐漸衰退
EN: to decline in quality, power, or vigor
翻譯: （品質、力量、活力）逐漸衰退、衰弱
- 4
科學衰變
EN: to undergo radioactive decay
翻譯: （物理）放射性衰變
小提醒：注意區分具體的「腐爛」(如食物)與抽象的「衰退」(如道德、帝國)，後者常用於社會或文明層面。
發音（How to Pronounce "Decay" in English）
How to pronounce "Decay" in English?"Decay" US vs UK pronunciation
點擊下方的 US / UK 按鈕可播放發音。
Real-life Examples of "Decay" from YouTube Videos
The strange politics of disgust | David Pizarro
TED
“The philosopher Martha Nussbaum points this out in this quote: "Thus, throughout history, certain disgust properties -- sliminess, bad smell, stickiness, decay, foulness -- have been repeatedly and monotonously been associated with Jews, women, homosexuals, untouchables, lower-class people -- all of those are imagined as tainted by the dirt of the body".”
(1 out of 6)
Definitions（定義）
What are the definitions of "Decay"?How does "Decay" change by context?
2. to gradually become weaker or worse in quality
（力量、品質）逐漸衰弱，衰退，惡化
The old empire slowly decayed over centuries.
那個古老的帝國在數個世紀中逐漸衰敗。
Without maintenance, the building's structure decayed.
缺乏維護，這棟建築的結構逐漸惡化。
3. (in physics) for a radioactive substance to change into a different form by releasing radiation
（物理學中放射性物質）衰變
Uranium atoms decay over time, releasing energy.
鈾原子會隨時間衰變，釋放出能量。
Scientists can measure how quickly the isotope decays.
科學家可以測量該同位素的衰變速度。
Grammar & Patterns（句型）
What are common sentence patterns for "Decay"?How to make natural sentences with "Decay"?
| Pattern | Meaning | Example |
|---|---|---|
| decay | （自然）腐爛、腐朽 | The wooden fence began to decay after years of rain. (木籬笆在多年風吹雨打後開始腐朽。) |
| decay + (adv.) | （逐漸）衰敗、惡化 | The city's infrastructure is decaying rapidly. (這座城市的基礎設施正在迅速惡化。) |
| decay into + noun | 衰敗成…、退化為… | The peaceful protest decayed into chaos. (和平抗議演變成了混亂。) |
| be decaying | 正在腐壞/衰敗中 | The fruit left on the counter is decaying. (留在檯面上的水果正在腐壞。) |
| start/begin to decay | 開始腐壞/衰敗 | Without proper care, the historical building will start to decay. (若沒有妥善維護，這棟歷史建築將會開始衰敗。) |
用法說明
How is "Decay" different from similar structures?What usage mistakes are common with "Decay"?
decay vs. be decaying
- decay 通常用作狀態動詞，描述一個已經存在且持續的腐爛、衰敗狀態。它強調的是結果或性質。
- be decaying 則強調腐爛、衰敗這個過程正在進行中，更具動態感。
- 在描述自然科學現象或抽象概念的衰退時，兩者常可互換，但語感略有不同。
- 在口語中，簡單現在式的 decay 更為常見，除非特別想強調「正在發生」的過程。 EN: Organic matter will decay over time, returning nutrients to the soil. 翻譯: 有機物質會隨時間腐爛，將養分歸還土壤。
EN:The fallen leaves are decaying rapidly in the damp forest.
翻譯:落葉在潮濕的森林裡正快速腐爛。
EN:Without maintenance, the city's infrastructure continues to decay.
翻譯:缺乏維護，這座城市的基礎設施持續衰敗。
EN:The old wooden pier is decaying and is no longer safe to walk on.
翻譯:那座舊木碼頭正在腐朽，走上去已經不安全了。
總結建議
描述普遍現象或狀態時用 decay，若想特別強調「正在發生」的過程則用 be decaying。
易混淆對比
What is the difference between "Decay" and similar words?How to choose "Decay" vs alternatives?
decay vs rot
「decay」和「rot」都指腐壞，但「decay」較為正式、中性，可指自然或緩慢的分解過程，包括抽象事物（如文明、記憶）的衰退；「rot」則更口語、具體，常指有機物（如食物、木材）因細菌或真菌作用而腐爛，帶有更強烈的負面意象。
decay vs decompose
「decay」和「decompose」都涉及物質分解，但「decompose」是更技術性、科學性的術語，強調生物或化學過程將物質分解為更簡單的成分；「decay」用法更廣泛，除物理分解外，也常用於描述力量、制度或狀態的逐漸惡化。
decay vs deteriorate
「decay」和「deteriorate」都表示變差，但「deteriorate」泛指任何方面（如健康、關係、局勢）的惡化，不必然涉及物理分解；「decay」則通常指因時間或自然力導致的物理性腐壞，或用於比喻抽象事物的逐漸衰落。
口語用法
How is "Decay" used in spoken English?What is the spoken vs formal difference for "Decay"?
引述
在對話中，當引述或轉述他人對某事物正在衰敗的看法時，常用「decay」來表達。 EN: He kept saying that the whole system is in decay and nobody's doing anything about it. 翻譯: 他不停說整個系統都在腐敗，卻沒人採取任何行動。
EN:So you think the neighborhood has decayed since the factory closed?
翻譯:所以你是覺得自從工廠關閉後，這社區就衰敗了？
語氣強調
在口語中，常與「really」、「just」或「totally」等副詞連用，以強調衰敗的程度或速度。 EN: Without regular maintenance, the wooden structure just decayed within a few years. 翻譯: 缺乏定期維護，木結構在幾年內就徹底腐朽了。
EN:The moral standards in that industry have really decayed, it's shocking.
翻譯:那個行業的道德標準真的敗壞了，很令人震驚。
停頓填充
在思考或組織語句時，有時會用「decay」相關的短語作為填充，帶出負面變化的話題。 EN: What we're seeing is... a kind of social decay, you know? 翻譯: 我們現在看到的是一種...社會的腐化，你懂吧？
EN:The problem is the decay of... um... public trust in institutions.
翻譯:問題在於...嗯...公眾對機構信任的流失。
正式寫作注意：在正式或學術寫作中，應避免使用口語化的填充詞（如「you know」、「um」），並選擇更精確的詞彙（如「deterioration」、「decomposition」、「degeneration」）來替代較為籠統的「decay」，以符合文體要求。
常見短語
What common collocations use "Decay"?What fixed phrases with "Decay" should I remember?
decay into
decay into something
逐漸腐爛、分解或演變成（更差的狀態）
decay rapidly
decay rapidly/quickly
迅速腐壞、衰敗
begin to decay
begin/start to decay
開始腐爛、衰敗
moral decay
moral/social/political decay
道德/社會/政治腐敗、淪喪
tooth decay
tooth/dental decay
蛀牙
fall into decay
fall into decay/disrepair
陷入破敗、失修的狀態
radioactive decay
radioactive decay
放射性衰變
slow decay
slow/gradual decay
緩慢的腐朽、衰敗
常見錯誤
What are common mistakes with "Decay"?Which "Decay" sentences look correct but are wrong?
×The wood is decaying.
✓The wood is decaying.
雖然文法正確，但作為動詞，'decay' 通常描述一個較慢、漸進的過程，而非瞬間狀態。在口語中，'rotting' 或 'decomposing' 可能更常用來描述正在進行的明顯腐壞。'decay' 更常出現在書面或正式描述中，或與抽象概念（如道德、制度）連用。
×His teeth decayed because he ate too much sugar.
✓His teeth decayed because he ate too much sugar. / He got tooth decay from eating too much sugar.
句子本身正確，但學習者常混淆動詞 'decay' 與名詞 'decay'（尤指 'tooth decay'）的用法。描述牙齒狀況時，更常見的說法是 'He has tooth decay' 或 'He got cavities'。動詞 'decay' 用於牙齒時，聽起來較為書面或科學化。
×The food decayed in just one hour.
✓The food spoiled/went bad in just one hour.
'Decay' 通常指一個相對緩慢的腐爛、分解過程（如木材、落葉、牙齒）。食物在短時間內（幾小時）變質，更自然的用詞是 'spoil', 'go bad', 或 'rot'。用 'decay' 形容食物快速變質會顯得不自然。
×I decayed my old books.
✓My old books decayed. / My old books deteriorated.
'Decay' 是不及物動詞，不能用於及物結構（如 *decay something*）。它描述主語自身發生的狀態變化，不能帶有直接賓語。正確的用法是主語（如 books, wood, teeth）自行 'decay'。若要表達人為導致損壞，應使用 'damage', 'ruin', 或 'cause ... to decay'。
×His health is decaying day by day.
✓His health is deteriorating/declining/failing day by day.
雖然 'decay' 可用於抽象概念的衰敗（如道德、文明），但描述人的 'health'（健康狀況）惡化時，更自然、常見的用詞是 'deteriorate', 'decline', 或 'fail'。'Decay' 用於健康會顯得太過 literal（像肉體腐爛）或過於詩意/書面。
×The building decayed after the earthquake.
✓The building collapsed/fell apart/was damaged after the earthquake. / The building decayed over many decades of neglect.
'Decay' 強調因時間、自然因素（如風雨、蟲蛀）導致的緩慢、漸進的破敗過程。地震造成的瞬間或短期結構損壞，應用 'collapse', 'be damaged', 或 'fall apart'。'Decay' 更適用於因長期閒置、缺乏維護而慢慢破敗的情況。
詞形變化
What are the word forms of "Decay"?What are tense/participle forms of "Decay"?
decays(3rd_singular)decaying(present_participle)decayed(past)decayed(past_participle)