tack has 23 distinct synonyms spread across 8 of its 12 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 heading or position of a vessel relative to the trim of its sails
a short nail with a sharp point and a large head
(nautical) a line (rope or chain) that regulates the angle at which a sail is set in relation to the wind
Synonyms, antonyms and the broader and narrower relations for tack come from Princeton University’s WordNet. Full sources and licences.
create by putting components or members together
“She pieced a quilt”
reverse (a direction, attitude, or course of action)