fancy up vs prank

fancy up is not a noun while prank is a noun.

Word	Noun	Adjective	Verb	Adverb
fancy up	No	No	Yes	No
prank	Yes	No	Yes	No

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

fancy up: put on special clothes to appear particularly appealing and attractive
prank: dress up showily

Other hyponyms of fancy up include dress, plume, preen, primp, tart up, enrobe, bedizen, dizen.

fancy up (noun)	prank (noun)
	a ludicrous or grotesque act done for fun and amusement
	acting like a clown or buffoon

fancy up (verb)	prank (verb)
put on special clothes to appear particularly appealing and attractive	dress up showily
	dress or decorate showily or gaudily