unpaired vs mismatched

unpaired and mismatched both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unpaired	No	Yes	No	No
mismatched	No	Yes	No	No

unpaired (adjective)	mismatched (adjective)
of the remaining member of a pair	either not matched or unsuitably matched
	(of a contest or contestants) not fairly matched as opponents