waif vs nestling

waif and nestling both are nouns.

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

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

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

waif (noun)	nestling (noun)
a homeless child especially one forsaken or orphaned	young bird not yet fledged
	a young person of either sex