n.

1. 愚蠢；愚笨[U]
   My folly has cost me dearly.

   我的愚蠢使我损失惨重。

2. 蠢事，愚行；傻念头[C]
   The old man felt regret for the follies of his youth.

   老人很后悔他年轻时的愚行。

   It would be folly to quit your job before finding a new one.

   在你找到新的工作前就辞职是不明智的。

3. 造价高而无用的怪异建筑物[C]

n.

1. foolishness.
2. an ornamental building with no practical purpose, especially a tower or mock-Gothic ruin in a large garden or park.
3. (Follies) a theatrical revue with glamorous female performers.