means The cardinal direction opposite north, toward the bottom of a conventionally oriented map and, in the Northern Hemisphere, toward the warmer latitudes.

from From Old English 'suth,' tracing back to a Proto-Germanic root (think Old Saxon and Old High German cousins). The deeper sense may be 'the sunward side' — possibly linked to the same ancient root as 'sun' — because for people living in the Northern Hemisphere, that's where the sun rides highest across the sky. The direction was literally named for where the daylight pooled.