[informal] flip [adjective] - not serious about a serious subject, in an attempt to be amusing or to appear cleverIt's easy to be flippant, but we have a serious problem to deal with.I'm tired of your flippant remarks/comments/attitude - please take the matter more seriously.
FLIPPANT
Meaning of FLIPPANT in English
Cambridge English vocab. Кембриджский английский словарь. 2012