specification vs specify

specification is a noun but specify is not a noun.

Word	Noun	Adjective	Verb	Adverb
specification	Yes	No	No	No
specify	No	No	Yes	No

specification (noun)	specify (noun)
a restriction that is insisted upon as a condition for an agreement
a detailed description of design criteria for a piece of work
naming explicitly
(patent law) a document drawn up by the applicant for a patent of invention that provides an explicit and detailed description of the nature and use of an invention

specification (verb)	specify (verb)
	design or destine
	define clearly
	select something or someone for a specific purpose
	be specific about
	decide upon or fix definitely
	specify as a condition or requirement in a contract or agreement; make an express demand or provision in an agreement
	determine the essential quality of