rack up vs lay

rack up is not a noun while lay is a noun.

Word	Noun	Adjective	Verb	Adverb
rack up	No	No	Yes	No
lay	Yes	Yes	Yes	No

As verbs, lay is a hypernym of rack up; that is, lay is a word with a broader meaning than rack up:

Other hypernyms of rack up include place, pose, position, put, set.

rack up (noun)	lay (noun)
	a narrative poem of popular origin
	a narrative song with a recurrent refrain

rack up (adjective)	lay (adjective)
	not of or from a profession
	characteristic of those who are not members of the clergy

rack up (verb)	lay (verb)
supply a rack with feed for (horses or other animals)	put in a horizontal position
defeat thoroughly	put into a certain place or abstract location
gain points in a game	lay eggs
place in a rack	prepare or position for action or operation
	impose as a duty, burden, or punishment