na-adjective, noun
flippant; frivolous; thoughtless
Describes speech, attitude, or behavior that is shallow, lacking seriousness, or inappropriately light-hearted. Often used in formal or written contexts.
彼の軽佻な発言が会議の雰囲気を悪くした。
His flippant remark soured the atmosphere of the meeting.
軽佻な態度は社会人としてふさわしくない。
A frivolous attitude is not appropriate for a working adult.