pick has 24 distinct synonyms spread across 15 of its 21 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.
harass with constant criticism
“Don't always pick on your little brother”
remove in small bits
“pick meat from a bone”
a small thin device (of metal or plastic or ivory) used to pluck a stringed instrument
a basketball maneuver; obstructing an opponent with one's body
“he was called for setting an illegal pick”
Synonyms, antonyms and the broader and narrower relations for pick come from Princeton University’s WordNet. Full sources and licences.