ut has 11 distinct synonyms spread across 3 of its 3 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 local time at the 0 meridian passing through Greenwich, England; it is the same everywhere
a state in the western United States; settled in 1847 by Mormons led by Brigham Young
the syllable naming the first (tonic) note of any major scale in solmization
Synonyms, antonyms and the broader and narrower relations for ut come from Princeton University’s WordNet. Full sources and licences.