solubility has 1 distinct synonym 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 insolubility.
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 quantity of a particular substance that can dissolve in a particular solvent (yielding a saturated solution)
the property (of a problem or difficulty) that makes it possible to solve
Synonyms, antonyms and the broader and narrower relations for solubility come from Princeton University’s WordNet. Full sources and licences.
the quality of being soluble and easily dissolved in liquid