rise up vs rebel

rise up is not a noun while rebel is a noun.

Word	Noun	Adjective	Verb	Adverb
rise up	No	No	Yes	No
rebel	Yes	No	Yes	No

As verbs, rise up and rebel are synonyms defined as:

rise up and rebel: take part in a rebellion; renounce a former allegiance

Other synonyms of rise up include arise, rise.

rise up (noun)	rebel (noun)
	a person who takes part in an armed rebellion against the constituted authority (especially in the hope of improving conditions)
	someone who exhibits great independence in thought and action

rise up (verb)	rebel (verb)
come to the surface	take part in a rebellion; renounce a former allegiance
stand up on the hind legs, of quadrupeds	break with established customs
take part in a rebellion; renounce a former allegiance