inpatient has 1 distinct synonym spread across 1 of its 1 sense. 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 outpatient.
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.
a patient who is residing in the hospital where he is being treated
Synonyms, antonyms and the broader and narrower relations for inpatient come from Princeton University’s WordNet. Full sources and licences.