day boarder vs dayboy

day boarder and dayboy both are nouns.

Word	Noun	Adjective	Verb	Adverb
day boarder	Yes	No	No	No
dayboy	Yes	No	No	No

As nouns, dayboy is a hyponym of day boarder; that is, dayboy is a word with a more specific, narrower meaning than day boarder:

day boarder: a schoolchild at a boarding school who has meals at school but sleeps at home
dayboy: a day boarder who is a boy

Other hyponyms of day boarder include daygirl.

day boarder (noun)	dayboy (noun)
a schoolchild at a boarding school who has meals at school but sleeps at home	a day boarder who is a boy