Witty, humorous, facetious, jocular, jocose are comparable when they apply to persons and their utterances and mean provoking or intended to provoke laughter or smiles.
Witty (compare WIT ) suggests a high degree of cleverness and quickness in discerning amusing congruities or incongruities; it may connote sparkling pleasantry, especially in repartee, but it often suggests sarcasm or causticity.
Humorous is a generic term applied to whoever or whatever provokes laughter. As opposed to witty , humorous often suggests sensibility rather than intellect, sympathy rather than aloofness in criticism, and sometimes, whimsicality rather than direct insight; thus, Pope is often described as a witty , Burns as a humorous , poet.
Facetious usually applies to clumsy or inappropriate jesting or, somewhat derogatorily, to attempts at wittiness or humorousness that please their maker more than others.
Jocular also implies a fondness for jesting and joking but suggests as its motive the desire to make others laugh or to keep them amused. It need not imply loquaciousness but it tends to suggest a sustained jolly mood or habit of temperament.
Jocose suggests waggishness or sportiveness in jesting and joking; it often comes close to facetious in suggesting clumsy inappropriate jesting.