n. pl. fol·lies
1. Lack of good sense, understanding, or foresight: an act of folly
a. An act or instance of foolishness: regretted the follies of his youth.
b. A costly undertaking having an absurd or ruinous outcome.
3. follies (used with a sing. or pl. verb) An elaborate theatrical revue consisting of music, dance, and skits.
4. A structure, such as a pavilion in a garden, that is chiefly decorative rather than practical in purpose.
[Middle English folie, from Old French, from fol, foolish, from Late Latin follis, windbag, fool; see FOOL.]
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