Synonyms of the word 
FACETIOUSLY → JOKINGLY - TONGUE-IN-CHEEK
facetiously
- adv. In a facetious or flippant manner; in a manner that treats serious issues with deliberately inappropriate…
- adv. (dated) In a pleasantly humorous or playful fashion.
jokingly
- adv. In a joking manner.
tongue-in-cheek
- adj. (idiomatic) Not intended seriously; jocular or humorous.
- adv. (obsolete) With contempt.
- adv. With irony.
If you are interested in words, visit the following sites :
- wiktionary.org/facetiously For complete definition of a word
- 1word.ws/facetiously to play with words, suffixs, prefixs, etc.