screw up vs screwup

screw up is not a noun while screwup is a noun.

Word	Noun	Adjective	Verb	Adverb
screw up	No	No	Yes	No
screwup	Yes	No	No	No

screw up (noun)	screwup (noun)
	the complete mismanagement or mishandling of a situation

screw up (verb)	screwup (verb)
twist into a strained configuration
make more intense
screw or turn higher
make a mess of, destroy or ruin