incompatibility 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 compatibility.
the relation between propositions that cannot both be true at the same time
(immunology) the degree to which the body's immune system will try to reject foreign material (as transfused blood or transplanted tissue)
Synonyms, antonyms and the broader and narrower relations for incompatibility come from Princeton University’s WordNet. Full sources and licences.
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 quality of being unable to exist or work in congenial combination