ring has 25 distinct synonyms spread across 13 of its 15 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 characteristic sound
“it has the ring of sincerity”
a toroidal shape
“a ring of ships in the harbor”
a rigid circular band of metal or wood or other material used for holding or fastening or hanging or pulling
“there was still a rusty iron hoop for tying a horse”
(chemistry) a chain of atoms in a molecule that forms a closed loop
an association of criminals
“police tried to break up the gang”
the sound of a bell ringing
“the distinctive ring of the church bell”
a platform usually marked off by ropes in which contestants box or wrestle
jewelry consisting of a circlet of precious metal (often set with jewels) worn on the finger
“she had rings on every finger”
get or try to get into communication (with someone) by telephone
“I tried to call you all night”
Synonyms, antonyms and the broader and narrower relations for ring come from Princeton University’s WordNet. Full sources and licences.