farm boy vs male child

farm boy and male child both are nouns.

Word	Noun	Adjective	Verb	Adverb
farm boy	Yes	No	No	No
male child	Yes	No	No	No

As nouns, male child is a hypernym of farm boy; that is, male child is a word with a broader meaning than farm boy:

Other hypernyms of farm boy include boy.

farm boy (noun)	male child (noun)
a boy who has grown up on a farm	a youthful male person