lad vs boy

lad and boy both are nouns.

Word	Noun	Adjective	Verb	Adverb
lad	Yes	No	No	No
boy	Yes	No	No	No

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

Other hypernyms of lad include male child.

lad (noun)	boy (noun)
a male child (a familiar term of address to a boy)	a youthful male person
a boy or man	(ethnic slur) offensive and disparaging term for Black man
	a friendly informal reference to a grown man
	a male human offspring