dissent vs walk out

dissent is a noun but walk out is not a noun.

Word	Noun	Adjective	Verb	Adverb
dissent	Yes	No	Yes	No
walk out	No	No	Yes	No

As verbs, walk out is a hyponym of dissent; that is, walk out is a word with a more specific, narrower meaning than dissent:

Other hyponyms of dissent include strike, demonstrate, march, arise, rebel, rise, rise up, rebel, renegade.

dissent (noun)	walk out (noun)
the act of protesting; a public (often organized) manifestation of dissent
(law) the difference of one judge's opinion from that of the majority
a difference of opinion

dissent (verb)	walk out (verb)
withhold assent	leave suddenly, often as an expression of disapproval
be of different opinions	leave abruptly, often in protest or anger
express opposition through action or words	stop work in order to press demands