antipodean vs antipodal

antipodean is not a noun while antipodal is a noun.

Word	Noun	Adjective	Verb	Adverb
antipodean	No	Yes	No	No
antipodal	Yes	Yes	No	No

As adjectives, antipodean and antipodal are synonyms defined as:

antipodean and antipodal: relating to the antipodes or situated at opposite sides of the earth

antipodean (noun)	antipodal (noun)
	the relation of opposition along a diameter

antipodean (adjective)	antipodal (adjective)
relating to the antipodes or situated at opposite sides of the earth	relating to the antipodes or situated at opposite sides of the earth