1. 荒诞;愚蠢
If you describe someone's behaviour as lunacy, you mean that it seems very strange or foolish.
2. 精神错乱
Lunacy is severe mental illness.
1. foolish or senseless behavior
Synonym: follyfoolerytomfoolerycrazinessindulgence
2. obsolete terms for legal insanity
Synonym: madnessinsaneness