poll has 7 distinct synonyms spread across 5 of its 9 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.
an inquiry into public opinion conducted by interviewing a random sample of people
the counting of votes (as in an election)
get the opinions (of people) by asking specific questions
vote in an election at a polling station
Synonyms, antonyms and the broader and narrower relations for poll come from Princeton University’s WordNet. Full sources and licences.