slap-up vs great

slap-up is not a noun while great is a noun.

Word	Noun	Adjective	Verb	Adverb
slap-up	No	Yes	No	No
great	Yes	Yes	No	No

As adjectives, slap-up and great are synonyms defined as:

Other synonyms of slap-up include bang-up, bully, corking, cracking, dandy, groovy, keen, neat, nifty, not bad, old, peachy, smashing, swell.

slap-up (noun)	great (noun)
	a person who has achieved distinction and honor in some field

slap-up (adjective)	great (adjective)
excellent	excellent
	in an advanced stage of pregnancy
	uppercase
	remarkable or out of the ordinary in degree or magnitude or effect
	of major significance or importance
	relatively large in size or number or extent; larger than others of its kind