protrude vs bulge

protrude is not a noun while bulge is a noun.

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

As verbs, protrude and bulge are synonyms defined as:

Other synonyms of protrude include pouch.

As verbs, protrude and bulge are synonyms defined as:

Other synonyms of protrude include bug out, bulge out, come out, pop, pop out, start.

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

Other hyponyms of protrude include overhang, push up, thrust, spear, spear up, bag, cantilever.

protrude (noun)	bulge (noun)
	something that bulges out or is protuberant or projects from its surroundings

protrude (verb)	bulge (verb)
swell or protrude outwards	swell or protrude outwards
bulge outward	cause to bulge or swell outwards
extend out or project in space	bulge outward
	bulge out; form a bulge outward, or be so full as to appear to bulge