valency vs polyvalent

valency is a noun but polyvalent is not a noun.

Word	Noun	Adjective	Verb	Adverb
valency	Yes	No	No	No
polyvalent	No	Yes	No	No

valency (noun)	polyvalent (noun)
(chemistry) a property of atoms or radicals; their combining power given in terms of the number of hydrogen atoms (or the equivalent)
(biology) a relative capacity to unite or react or interact as with antigens or a biological substrate
the phenomenon of forming chemical bonds

valency (adjective)	polyvalent (adjective)
	having more than one valence, or having a valence of 3 or higher
	containing several antibodies each capable of counteracting a specific antigen