sou'west vs southwest

sou'west is not a noun while southwest is a noun.

Word	Noun	Adjective	Verb	Adverb
sou'west	No	No	No	Yes
southwest	Yes	Yes	No	Yes

As adverbs, sou'west and southwest are synonyms defined as:

Other synonyms of sou'west include south-west.

sou'west (noun)	southwest (noun)
	a location in the southwestern part of a country, region, or city
	the compass point midway between south and west; at 225 degrees
	the direction corresponding to the southwestward compass point

sou'west (adjective)	southwest (adjective)
	situated in or oriented toward the southwest
	coming from the southwest

sou'west (adverb)	southwest (adverb)
to, toward, or in the southwest	to, toward, or in the southwest