stand up vs bristle

stand up is not a noun while bristle is a noun.

Word	Noun	Adjective	Verb	Adverb
stand up	No	No	Yes	No
bristle	Yes	No	Yes	No

As verbs, stand up and bristle are synonyms defined as:

Other synonyms of stand up include uprise.

stand up (noun)	bristle (noun)
	a stiff hair
	a stiff fiber (coarse hair or filament); natural or synthetic

stand up (verb)	bristle (verb)
defend against attack or criticism	react in an offended or angry manner
refuse to back down; remain solid under criticism or attack	rise up as in fear
be standing; be upright	be in a state of movement or action
put into an upright position	have or be thickly covered with or as if with bristles
rise to one's feet
rise up as in fear
resist or withstand wear, criticism, etc.