gravitation has 3 distinct synonyms spread across 1 of its 3 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 one recorded opposite is levitation.
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.
(physics) the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface
“the more remote the body the less the gravity”
Synonyms, antonyms and the broader and narrower relations for gravitation come from Princeton University’s WordNet. Full sources and licences.
movement downward resulting from gravitational attraction
“irrigation by gravitation rather than by pumps”
a figurative movement toward some attraction
“the gravitation of the middle class to the suburbs”