gum has 7 distinct synonyms spread across 6 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.
a preparation (usually made of sweetened chicle) for chewing
the tissue (covered by mucous membrane) of the jaws that surrounds the bases of the teeth
any of various substances (soluble in water) that exude from certain plants; they are gelatinous when moist but harden on drying
cement consisting of a sticky substance that is used as an adhesive
any of various trees of the genera Eucalyptus or Liquidambar or Nyssa that are sources of gum
Synonyms, antonyms and the broader and narrower relations for gum come from Princeton University’s WordNet. Full sources and licences.