oversized vs outsize

oversized is not a noun while outsize is a noun.

Word	Noun	Adjective	Verb	Adverb
oversized	No	Yes	No	No
outsize	Yes	Yes	No	No

As adjectives, oversized and outsize are synonyms defined as:

Other synonyms of oversized include outsized, oversize.

oversized (noun)	outsize (noun)
	an unusual garment size (especially one that is very large)

oversized (adjective)	outsize (adjective)
larger than normal for its kind	larger than normal for its kind