Answer:
treating serious issues with deliberately inappropriate humor; flippant.
Step-by-step explanation:
Facetious is an adjective meaning “inappropriately humorous.” It can also be used in a less negative way to mean “amusing” or, more negatively, to describe someone as “treating serious issues lightly.” Examples: Facetious in a sentence Helena doesn't like Leo because he made a facetious remark at her wedding.