flippant
Flippant is an adjective used to describe a remark, attitude, or demeanor that shows a lack of proper respect or seriousness about a topic. A flippant comment treats important matters with glibness or levity, often implying insolence or contempt. The term suggests that the speaker is not taking others’ concerns, conventions, or consequences seriously, rather than simply being humorous.
In usage, flippant remarks are typically seen as inappropriate in formal or sensitive contexts, such as discussions
Flippant is the standard modern form; related forms include flippancy (the noun) and flippantly (the adverb).
Antonyms include serious, solemn, earnest, and respectful. Related terms include glib, facetious, and sardonic, though each