facetious vs sarcastic definition
I often get answers collapsed on Quora because they are facetious; the admins see these as jokes. Sarcastic, on the other hand, means using words to mean the opposite of what they usually do, especially to convey contempt.
Facetious does mean not to be taken seriously or literally, a good definition that says a lot in few words. Not to be taken addresses intent, specifically lack of ill intent. ...seriously or literally brings in the word play involved, where one says something that is the opposite of what is meant.