condensation has 7 distinct synonyms spread across 4 of its 6 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.
(psychoanalysis) an unconscious process whereby two ideas or images combine into a single symbol; especially in dreams
the process of changing from a gaseous to a liquid or solid state
atmospheric moisture that has condensed because of cold
the process or result of becoming smaller or pressed together
“the contraction of a gas on cooling”
the act of increasing the density of something
Synonyms, antonyms and the broader and narrower relations for condensation come from Princeton University’s WordNet. Full sources and licences.