link has 21 distinct synonyms spread across 11 of its 13 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 state of being connected
“the connection between church and state is inescapable”
a unit of length equal to 1/100 of a chain
(computing) an instruction that connects one part of a program or an element on a list to another program or list
a channel for communication between groups
“he provided a liaison with the guerrillas”
a two-way radio communication system (usually microwave); part of a more extensive telecommunication network
connect, fasten, or put together two or more pieces
“Can you connect the two loudspeakers?”
Synonyms, antonyms and the broader and narrower relations for link come from Princeton University’s WordNet. Full sources and licences.