southerly vs south wind

southerly and south wind both are nouns.

Word	Noun	Adjective	Verb	Adverb
southerly	Yes	Yes	No	Yes
south wind	Yes	No	No	No

As nouns, southerly and south wind are synonyms defined as:

Other synonyms of southerly include souther.

southerly (noun)	south wind (noun)
a wind from the south	a wind from the south

southerly (adjective)	south wind (adjective)
from the south; used especially of wind
situated in or oriented toward the south

southerly (adverb)	south wind (adverb)
from the south
toward the south