Antonyms of adj facetious

1 sense of facetious

Sense 1
bantering, facetious, tongue-in-cheek -- (cleverly amusing in tone; "a bantering tone"; "facetious remarks"; "tongue-in-cheek advice")

INDIRECT (VIA humorous) -> humorless, humourless, unhumorous -- (lacking humor; "it was a humorless wink; a wink of warning"- Truman Capote)

Similarity of adj facetious

1 sense of facetious

Sense 1
bantering, facetious, tongue-in-cheek -- (cleverly amusing in tone; "a bantering tone"; "facetious remarks"; "tongue-in-cheek advice")
       => humorous (vs. humorless), humourous -- (full of or characterized by humor; "humorous stories"; "humorous cartoons"; "in a humorous vein")