penis vs cock

penis and cock both are nouns.

Word	Noun	Adjective	Verb	Adverb
penis	Yes	No	No	No
cock	Yes	No	Yes	No

As nouns, cock is a hyponym of penis; that is, cock is a word with a more specific, narrower meaning than penis:

Other hyponyms of penis include dick, pecker, prick, putz, shaft, tool, micropenis, microphallus, erection, hard-on.

penis (noun)	cock (noun)
the male sex organ	adult male bird
	adult male chicken
	faucet consisting of a rotating device for regulating flow of a liquid
	the part of a gunlock that strikes the percussion cap when the trigger is pulled
	obscene terms for penis

penis (verb)	cock (verb)
	set the trigger of a firearm back for firing
	to walk with a lofty proud gait, often in an attempt to impress others
	tilt or slant to one side