south has 10 distinct synonyms spread across 3 of its 7 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 north.
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.
the region of the United States lying to the south of the Mason-Dixon line
the southern states that seceded from the United States in 1861
the cardinal compass point that is at 180 degrees
a location in the southern part of a country, region, or city
the direction corresponding to the southward cardinal compass point
situated in or facing or moving toward or coming from the south
“the south entrance”
Synonyms, antonyms and the broader and narrower relations for south come from Princeton University’s WordNet. Full sources and licences.