compact has 20 distinct synonyms spread across 9 of its 10 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 loose.
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 small cosmetics case with a mirror; to be carried in a woman's purse
a signed written agreement between two or more parties (nations) to perform some action
closely and firmly united or packed together
“compact soil”
briefly giving the gist of something
“a short and compendious book”
Synonyms, antonyms and the broader and narrower relations for compact come from Princeton University’s WordNet. Full sources and licences.