pass up vs refuse

pass up is not a noun while refuse is a noun.

Word	Noun	Adjective	Verb	Adverb
pass up	No	No	Yes	No
refuse	Yes	No	Yes	No

As verbs, pass up and refuse are synonyms defined as:

Other synonyms of pass up include decline, reject, turn down.

pass up (noun)	refuse (noun)
	food that is discarded (as from a kitchen)

pass up (verb)	refuse (verb)
fail to acknowledge	show unwillingness towards
not accept as true	not accept as true
	refuse to let have
	refuse entrance or membership
	elude, especially in a baffling way
	resist immunologically the introduction of some foreign tissue or organ