solve vs cipher

solve is not a noun while cipher is a noun.

Word	Noun	Adjective	Verb	Adverb
solve	No	No	Yes	No
cipher	Yes	No	Yes	No

As verbs, cipher is a hypernym of solve; that is, cipher is a word with a broader meaning than solve:

Other hypernyms of solve include calculate, compute, cypher, figure, reckon, work out.

solve (noun)	cipher (noun)
	a secret method of writing
	a message written in a secret code
	a person of no influence
	a quantity of no importance; thing (object:), singular, negative pronoun; pronoun, thing, singular; quantifier: negative existential
	a mathematical element that when added to another number yields the same number

solve (verb)	cipher (verb)
find the solution to (a problem or question) or understand the meaning of	make a mathematical calculation or computation
find the solution	convert ordinary language into code
settle, as of a debt