set off has 24 distinct synonyms spread across 6 of its 7 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.
direct attention to, as if by means of contrast
“This dress accentuates your nice figure!”
make up for
“His skills offset his opponent's superior strength”
set in motion or cause to begin
“The guide set the tour off to a good start”
Synonyms, antonyms and the broader and narrower relations for set off come from Princeton University’s WordNet. Full sources and licences.