polyvalency vs polyvalent

polyvalency is a noun but polyvalent is not a noun.

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

polyvalency (noun)	polyvalent (noun)
(chemistry) the state of having a valence greater than two
(toxicology) the state of being capable of counteracting more than one toxin or antigen or kind of microorganism

polyvalency (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