sprog vs youngster

sprog and youngster both are nouns.

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

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

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

sprog (noun)	youngster (noun)
a child	a young person of either sex
a new military recruit