First you have to spell it correctly:
fa·ce·tious
Pronunciation: f&-'sE-sh&s
Function:
adjective
Etymology: Middle French
facetieux, from
facetie jest, from Latin
facetia
1 : joking or jesting often inappropriately
: WAGGISH <just being
facetious>
2 : meant to be humorous or funny
: not serious <a
facetious remark>
synonym see WITTY
-
fa·ce·tious·ly adverb
-
fa·ce·tious·ness noun
http://www.m-w.com/cgi-bin/dictionary?va=facetious