frivolity
noun [ C or U ] uk/frɪˈvɒl.ə.ti/ us/frɪˈvɑː.lə.t̬i/
愚蠢轻率所为；无关痛痒的事物
behaviour that is silly and not serious, or things that are silly and not important
You shouldn't treat such a serious subject with frivolity. 对待如此严肃的话题不能敷衍轻视。
I'm far too busy to waste time on frivolities like going to the cinema. 我忙得不可开交，不会把时间浪费在看电影之类无聊的事上。