良よい大人おとなMeaningsExpressionNoun1. (an) adult their age (should, should not, etc.); grown man (woman); person who is old enough (to know better) (oft. used sarcastically)Other readingsいい大人おとな良いい大人おとなKanji used良good大large人personComposed of良よいgood; excellent; fine; nice; pleasant; agreeable; sufficient; enough; ready; prepared; …I-adjective大人おとなadult; grown-upNoun