interior has 10 distinct synonyms spread across 6 of its 8 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 exterior.
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.
situated within or suitable for inside a building
“an interior scene”
the region that is inside of something
the United States federal department charged with conservation and the development of natural resources; created in 1849
1 of the 8 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for interior.
Synonyms, antonyms and the broader and narrower relations for interior come from Princeton University’s WordNet. Full sources and licences.