disposable has no recorded synonym. 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 nondisposable.
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.
free or available for use or disposition
“every disposable piece of equipment was sent to the fire”
designed to be disposed of after use
“disposable paper cups”
an item that can be disposed of after it has been used
Synonyms, antonyms and the broader and narrower relations for disposable come from Princeton University’s WordNet. Full sources and licences.