intramural 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 extramural.
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.
carried on within the bounds of an institution or community
“most of the students participated actively in the college's intramural sports program”
Synonyms, antonyms and the broader and narrower relations for intramural come from Princeton University’s WordNet. Full sources and licences.