His casual behaviour was wholly inappropriate for such a formal occasion. 他随便的举止在这样正式的场合十分不恰当。
I think it would be inappropriate (for you) to invite her to a party so soon after her husband's death. 我认为(你)在她丈夫刚去世不久便邀请她参加聚会是不合适的。
Synonyms: improper (WRONG) irregular (RULE) unacceptableunbecomingungentlemanlyunladylikeunprofessionalunsuitable
Opposite: appropriate