southern vs austral

southern is not a noun while austral is a noun.

Word	Noun	Adjective	Verb	Adverb
southern	No	Yes	No	No
austral	Yes	Yes	No	No

southern (noun)	austral (noun)
	the basic unit of money in Argentina; equal to 100 centavos

southern (adjective)	austral (adjective)
situated in or coming from regions of the south	of the south or coming from the south
in or characteristic of a region of the United States south of (approximately) the Mason-Dixon line
from the south; used especially of wind
situated in or oriented toward the south