facetious
adjective /fəˈsiːʃəs/
/fəˈsiːʃəs/
(disapproving)- trying to appear funny and clever at a time when other people do not think it is appropriate, and when it would be better to be serious
乱引人发笑的；不分场合耍聪明的 - a facetious comment/remark
不分场合耍聪明的议论 - Stop being facetious; this is serious.
别乱开玩笑，这是个严肃的事。
词源late 16th cent. (in the general sense ‘witty, amusing’): from French facétieux, from facétie, from Latin facetia ‘jest’, from facetus ‘witty’. - a facetious comment/remark