- Folly is defined as an act of foolishness or a lack of good sense.
- An example of folly is someone intentionally stabbing their foot with a pitch fork.
- An example of folly is building a hospital on an earthquake fault line.
folly definition by Webster's New World
- a lack of understanding, sense, or rational conduct; foolishness
- any foolish action or belief
- any foolish and useless but expensive undertaking
- Obsolete wickedness or evil; also, lewdness
- action that ends or can end in disaster
Origin: Middle English folie ; from Old French ; from fol: see fool
folly definition by American Heritage Dictionary
noun pl. fol·lies
- A lack of good sense, understanding, or foresight.
- a. An act or instance of foolishness: regretted the follies of his youth.b. A costly undertaking having an absurd or ruinous outcome.
- follies (used with a sing. or pl. verb) An elaborate theatrical revue consisting of music, dance, and skits.
- Obsolete a. Perilously or criminally foolish action.b. Evil; wickedness.c. Lewdness; lasciviousness.
Origin: Middle English folie, from Old French, from fol, foolish, from Late Latin follis, windbag, fool; see fool.