mistake vs slip up

mistake is a noun but slip up is not a noun.

Word	Noun	Adjective	Verb	Adverb
mistake	Yes	No	Yes	No
slip up	No	No	Yes	No

As verbs, slip up is a hyponym of mistake; that is, slip up is a word with a more specific, narrower meaning than mistake:

Other hyponyms of mistake include misremember, stumble, trip up, misjudge, fall for.

mistake (noun)	slip up (noun)
a wrong action attributable to bad judgment or ignorance or inattention
an understanding of something that is not correct
part of a statement that is not correct

mistake (verb)	slip up (verb)
to make a mistake or be incorrect	make an error
identify incorrectly