humor has 11 distinct synonyms spread across 7 of its 7 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a message whose ingenuity or verbal skill or incongruity has the power to evoke laughter
the trait of appreciating (and being able to express) the humorous
“she didn't appreciate my humor”
the quality of being funny
“I fail to see the humor in it”
(Middle Ages) one of the four fluids in the body whose balance was believed to determine your emotional and physical state
“the humors are blood and phlegm and yellow and black bile”
the liquid parts of the body
Synonyms, antonyms and the broader and narrower relations for humor come from Princeton University’s WordNet. Full sources and licences.