waif vs small fry

waif and small fry both are nouns.

Word	Noun	Adjective	Verb	Adverb
waif	Yes	No	No	No
small fry	Yes	No	No	No

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

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

waif (noun)	small fry (noun)
a homeless child especially one forsaken or orphaned	someone who is small and insignificant
	a young person of either sex