fa ‧ ce ‧ tious /fəˈsiːʃəs/ BrE AmE adjective
[ Date: 1500-1600 ; Language: French ; Origin: facétieux , from facétie 'joke' ]
saying things that are intended to be clever and funny but are really silly and annoying:
Don’t be so facetious!
facetious comments
—facetiously adverb
—facetiousness noun [uncountable]