spear up vs spear

spear up is not a noun while spear is a noun.

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

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

spear up (noun)	spear (noun)
	a long pointed rod used as a tool or weapon
	an implement with a shaft and barbed point used for catching fish

spear up (verb)	spear (verb)
thrust up like a spear	pierce with a spear
	thrust up like a spear