unit has 4 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.
any division of quantity accepted as a standard of measurement or exchange
“the dollar is the United States unit of currency”
Synonyms, antonyms and the broader and narrower relations for unit come from Princeton University’s WordNet. Full sources and licences.
an individual or group or structure or other entity regarded as a structural or functional constituent of a whole
“the reduced the number of units and installations”
an organization regarded as part of a larger social group
“the coach said the offensive unit did a good job”
an assemblage of parts that is regarded as a single entity
“how big is that part compared to the whole?”