facetious

Etymology

From French facétieux, from Latin facētia (“jest, wit, humor”), from facētus (“witty, jocose, facetious”).

adj

1. Treating serious issues with (often deliberately) inappropriate humour; flippant.
   Robbie's joke about Heather's appearance was just him being facetious.
   Glamour for its own sake is not something I have ever been particularly interested in,” Stella McCartney said backstage after her catwalk show. Which could sound like a facetious statement from a fashion designer who was, at that moment, standing among the marble-slabbed floors, elaborately frescoed ceilings and giant chandeliers of the Palais Garnier opera house, where the show was staged. October 2, 2017, Jess Cartner-Morle, “Stella McCartney lays waste to disposable fashion in Paris”, in the Guardian
2. Pleasantly humorous; jocular.
3. (Of an idea or statement) humorously silly or counterproductive for the purpose of sarcastically advocating the opposite.