facetiously

/fəˈsiʃəsli/

When you say something facetiously, you don't really mean it — you're joking. You might walk into your brother's room and facetiously say, "Wow, it's really clean in here."

People who say things facetiously are being a little bit sarcastic, saying one thing and meaning another, or treating a serious subject in a funny way. A disappointed friend might, for example, say facetiously, "That was the best birthday ever, especially since no one remembered!" The adjective facetious came first, and it means "flippant or joking," from the French facétie, "a joke." The Latin root is facetia, "jest or witticism."

Definitions of facetiously

1. adverb

   not seriously
   “I meant it facetiously”

   synonyms: jokingly, tongue-in-cheek