germicidal vs disinfectant

germicidal is not a noun while disinfectant is a noun.

Word	Noun	Adjective	Verb	Adverb
germicidal	No	Yes	No	No
disinfectant	Yes	Yes	No	No

As adjectives, germicidal and disinfectant are synonyms defined as:

germicidal and disinfectant: preventing infection by inhibiting the growth or action of microorganisms

Other synonyms of germicidal include bactericidal.

germicidal (noun)	disinfectant (noun)
	an agent (as heat or radiation or a chemical) that destroys microorganisms that might carry disease

germicidal (adjective)	disinfectant (adjective)
preventing infection by inhibiting the growth or action of microorganisms	preventing infection by inhibiting the growth or action of microorganisms