1 noun LAW, PSYCH mental illnessgealtacht fem3 c m uinsanity pleapléadáil ghealtachta2 noun foolishnessamaidí fem4 c m useafóid fem2 c m uit's time to stop this insanitytá sé in am deireadh a chur leis an amaidí seoit'd be insanity to do thatbheadh sé rí-amaideach é sin a dhéanamh