If you say that a particular action or way of behaving is folly or a folly, you mean that it is foolish.
例句
It's sheer folly to build nuclear power stations in a country that has dozens of earthquakes every year.在每年会发生几十次地震的国家建造核电站简直就是愚蠢至极。...a reminder of the follies of war.提醒人们战争之愚蠢的东西
N-COUNT
(尤指旧时英国花园等中的)装饰性建筑
A folly is a small tower or other unusual building that is built as a decoration in a large garden or park, especially in Britain in former times.
英汉词典释义
n.
愚蠢;蠢笨;愚蠢的行为、思想或做法
Events proved the folly of such calculations.事情的进展证明了这种估计是愚蠢的。He always sounds in folly.他总是表现出一副愚蠢的样子。He has given up youthful follies.他不再做年轻人的荒唐事了。I was betrayed into folly.我受蒙骗而做蠢事。