いい大人おとなMeaningsExpressionNoun1. (an) adult their age (should, should not, etc.); grown man (woman); person who is old enough (to know better) (oft. used sarcastically)Other spellings良いい大人おとなUsage share unknownOther readings良よい大人おとなKanji used大large人personKanji in other spellings良good