trip up vs trip

trip up is not a noun while trip is a noun.

Word	Noun	Adjective	Verb	Adverb
trip up	No	No	Yes	No
trip	Yes	No	Yes	No

As verbs, trip up and trip are synonyms defined as:

trip up (noun)	trip (noun)
	a journey for some purpose (usually including the return)
	an unintentional but embarrassing blunder
	a light or nimble tread
	a catch mechanism that acts as a switch
	an accidental misstep threatening (or causing) a fall
	an exciting or stimulating experience
	a hallucinatory experience induced by drugs

trip up (verb)	trip (verb)
detect a blunder or misstep	get high, stoned, or drugged
make an error	put in motion or move to act
cause to stumble	miss a step and fall or nearly fall
	cause to stumble
	make a trip for pleasure