capability has 3 distinct synonyms spread across 3 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 incapability.
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 capable -- physically or intellectually or legally
“he worked to the limits of his capability”
Synonyms, antonyms and the broader and narrower relations for capability come from Princeton University’s WordNet. Full sources and licences.
the susceptibility of something to a particular treatment
“the capability of a metal to be fused”
an aptitude that may be developed