From Longman Dictionary of Contemporary Englishfollyfol‧ly /ˈfɒli $ ˈfɑːli/ noun (plural follies) 1 [countable, uncountable] formalSTUPID/NOT SENSIBLE a very stupid thing to do, especially one that is likely to have serious results Somerville bitterly regretted his folly at becoming involved.it would be folly to do something It would be sheer folly to reduce spending on health education. the follies of aristocratic society2 [countable]AATBB an unusual building that was built in the past as a decoration, not to be used or lived in
Examples from the Corpus
folly• Is it mad to spend £1 million on a folly?• So far from abandoning our folly, we started pushing it as far as it would go.• Why was it designated romantic folly?• In fact, the only social folly I committed was to pretend I understood about contraception.• He dyed doves various bright colours to fly around and adorn the folly and the town.• Now they expect responsible customers to pay for their folly.sheer folly• I happen to believe in miracles, but it would be sheer folly to depend on them.• Throwing them away is sheer folly.• Their lack of ease with each other is tangible and to pretend otherwise is sheer folly.• In part two: A slice of history.The birthday cake that was sheer folly.Origin folly (1200-1300) Old French folie, from fol; → FOOL1 