changeling vs small fry

changeling and small fry both are nouns.

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

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

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

changeling (noun)	small fry (noun)
a child secretly exchanged for another in infancy	someone who is small and insignificant
a person of subnormal intelligence	a young person of either sex