prank vs practical joke

prank and practical joke both are nouns.

Word	Noun	Adjective	Verb	Adverb
prank	Yes	No	Yes	No
practical joke	Yes	No	No	No

As nouns, practical joke is a hyponym of prank; that is, practical joke is a word with a more specific, narrower meaning than prank:

prank: a ludicrous or grotesque act done for fun and amusement
practical joke: a prank or trick played on a person (especially one intended to make the victim appear foolish)

Other hyponyms of prank include dirty trick.

prank (noun)	practical joke (noun)
a ludicrous or grotesque act done for fun and amusement	a prank or trick played on a person (especially one intended to make the victim appear foolish)
acting like a clown or buffoon

prank (verb)	practical joke (verb)
dress up showily
dress or decorate showily or gaudily