imp vs youngster

imp and youngster both are nouns.

Word	Noun	Adjective	Verb	Adverb
imp	Yes	No	No	No
youngster	Yes	No	No	No

As nouns, youngster is a hypernym of imp; that is, youngster is a word with a broader meaning than imp:

Other hypernyms of imp include child, fry, kid, minor, nestling, nipper, shaver, small fry, tiddler, tike, tyke.

imp (noun)	youngster (noun)
one who is playfully mischievous	a young person of either sex
(folklore) fairies that are somewhat mischievous