bulk vs protrude

bulk is a noun but protrude is not a noun.

Word	Noun	Adjective	Verb	Adverb
bulk	Yes	No	Yes	No
protrude	No	No	Yes	No

As verbs, protrude is a hypernym of bulk; that is, protrude is a word with a broader meaning than bulk:

Other hypernyms of bulk include bulge, pouch.

bulk (noun)	protrude (noun)
the property of something that is great in magnitude
the property resulting from being or relating to the greater in number of two parts; the main part
the property possessed by a large mass

bulk (verb)	protrude (verb)
cause to bulge or swell outwards	swell or protrude outwards
stick out or up	bulge outward
to gain size and weight by means of exercise and diet	extend out or project in space