free has 30 distinct synonyms spread across 18 of its 22 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. Its 4 recorded opposites are confine, obstruct, unfree, bound.
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.
grant relief or an exemption from a rule or requirement to
“She exempted me from the exam”
make (information) available for publication
“release the list with the names of the prisoners”
let off the hook
“I absolve you from this responsibility”
part with a possession or right
“I am relinquishing my bedroom to the long-term house guest”
not limited or hampered; not under compulsion or restraint
“free enterprise”
unconstrained or not chemically bound in a molecule or not fixed and capable of relatively unrestricted motion
“free expansion”
not held in servitude
“after the Civil War he was a free man”
1 of the 22 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for free.
Synonyms, antonyms and the broader and narrower relations for free come from Princeton University’s WordNet. Full sources and licences.