offset has 21 distinct synonyms spread across 8 of its 11 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.
a horizontal branch from the base of plant that produces new plants from buds at its tips
a plate makes an inked impression on a rubber-blanketed cylinder, which in turn transfers it to the paper
compensate for or counterbalance
“offset deposits and withdrawals”
make up for
“His skills offset his opponent's superior strength”
cause (printed matter) to transfer or smear onto another surface
produce by offset printing
“offset the conference proceedings”
Synonyms, antonyms and the broader and narrower relations for offset come from Princeton University’s WordNet. Full sources and licences.