urge vs pep up

urge is a noun but pep up is not a noun.

Word	Noun	Adjective	Verb	Adverb
urge	Yes	No	Yes	No
pep up	No	No	Yes	No

As verbs, urge and pep up are synonyms defined as:

Other synonyms of urge include barrack, cheer, exhort, inspire, root on, urge on.

urge (noun)	pep up (noun)
a strong restless desire
an instinctive motive

urge (verb)	pep up (verb)
force or impel in an indicated direction	make more interesting or lively
spur on or encourage especially by cheers and shouts	spur on or encourage especially by cheers and shouts
push for something