名詞 folly:

1. the trait of acting stupidly or rashly
   同義詞：foolishness, unwiseness
2. a stupid mistake
   同義詞：stupidity, betise, foolishness, imbecility
3. the quality of being rash and foolish
   同義詞：foolishness, craziness, madness
4. foolish or senseless behavior
   同義詞：foolery, tomfoolery, craziness, lunacy, indulgence

1. Beauty and folly are often companions.
   [諺]美貌和愚蠢常結伴。
2. He bitterly repented his folly.
   他對自己干的蠢事後悔已極。
3. Zeal without knowledge is the sister of folly.
   [諺]無知的熱情近乎愚蠢。
4. He is repentant of his folly.
   他對自己的愚蠢行為而懊惱。
5. Our folly has undone us.
   我們的愚蠢行為將自己毀了。
6. The old man smiled sadly when he remembered the follies of his youth.
   這老人想起年輕時的荒唐事，不禁苦笑。
7. It is a great folly to try to persuade him.
   試圖說服他未免太愚蠢了。

fol.ly

n.（名詞）
【復數(shù)】 fol.lies
A lack of good sense, understanding, or foresight.
愚笨：良好的想法、理解和遠慮的缺乏

An act or instance of foolishness:
愚行，荒唐事：愚蠢的行為或事例：
例句：
regretted the follies of his youth.
為他年輕時的愚蠢行為而后悔

A costly undertaking having an absurd or ruinous outcome.
費力不討好的事：一項具有一個荒謬或毀滅性結果的代價很高的任務
follies (used with a sing. or pl. verb)An elaborate theatrical revue consisting of music, dance, and skits.
follies （與單數(shù)或復數(shù)動詞連用）時事諷刺?。河梢魳贰⑽璧负椭S刺文組成的精心制作的戲劇性時事諷刺劇
Obsolete
【廢語】
Perilously or criminally foolish action.
危險的蠢行：危險或犯法的愚蠢行為
Evil; wickedness.
壞；邪惡
Lewdness; lasciviousness.
卑劣；好色

來源：
Middle English folie
中古英語 folie
from Old French
源自 古法語
from fol [foolish]
源自 fol [愚蠢]
from Late Latin follis [windbag, fool] * see fool
源自 后期拉丁語 follis [空談者，傻子] *參見 fool