minus has 2 distinct synonyms spread across 2 of its 3 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 plus.
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.
on the negative side or lower end of a scale
“minus 5 degrees”
an arithmetic operation in which the difference between two numbers is calculated
“the subtraction of three from four leaves one”
Synonyms, antonyms and the broader and narrower relations for minus come from Princeton University’s WordNet. Full sources and licences.