negotiate vs bargain

negotiate is not a noun while bargain is a noun.

Word	Noun	Adjective	Verb	Adverb
negotiate	No	No	Yes	No
bargain	Yes	No	Yes	No

As verbs, bargain is a hyponym of negotiate; that is, bargain is a word with a more specific, narrower meaning than negotiate:

Other hyponyms of negotiate include arbitrate, intercede, intermediate, liaise, mediate, renegociate, renegotiate, dicker, broker.

negotiate (noun)	bargain (noun)
	an agreement between parties (usually arrived at after discussion) fixing obligations of each
	an advantageous purchase

negotiate (verb)	bargain (verb)
discuss the terms of an arrangement	come to terms; arrive at an agreement
succeed in passing through, around, or over	negotiate the terms of an exchange