peg has 13 distinct synonyms spread across 7 of its 10 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.
regulator that can be turned to regulate the pitch of the strings of a stringed instrument
pierce with a wooden pin or knock or thrust a wooden pin into
Synonyms, antonyms and the broader and narrower relations for peg come from Princeton University’s WordNet. Full sources and licences.
stabilize (the price of a commodity or an exchange rate) by legislation or market operations
“The weak currency was pegged to the US Dollar”