teasing has 18 distinct synonyms spread across 4 of its 6 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.
the act of harassing someone playfully or maliciously (especially by ridicule); provoking someone with persistent annoyances
“he ignored their teases”
playful vexation
“the parody was just a form of teasing”
causing irritation or annoyance
“tapping an annoying rhythm on his glass with his fork”
1 of the 6 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for teasing.
Synonyms, antonyms and the broader and narrower relations for teasing come from Princeton University’s WordNet. Full sources and licences.