urge on vs urge

urge on is not a noun while urge is a noun.

Word	Noun	Adjective	Verb	Adverb
urge on	No	No	Yes	No
urge	Yes	No	Yes	No

As verbs, urge on and urge are synonyms defined as:

Other synonyms of urge on include exhort, press.

As verbs, urge on and urge are synonyms defined as:

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

urge on (noun)	urge (noun)
	a strong restless desire
	an instinctive motive

urge on (verb)	urge (verb)
force or impel in an indicated direction	force or impel in an indicated direction
spur on or encourage especially by cheers and shouts	spur on or encourage especially by cheers and shouts
	push for something