imp vs nestling

imp and nestling both are nouns.

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

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

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

imp (noun)	nestling (noun)
one who is playfully mischievous	young bird not yet fledged
(folklore) fairies that are somewhat mischievous	a young person of either sex