renter vs boarder

renter and boarder both are nouns.

Word	Noun	Adjective	Verb	Adverb
renter	Yes	No	No	No
boarder	Yes	No	No	No

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

renter: someone who pays rent to use land or a building or a car that is owned by someone else
boarder: a tenant in someone's house

Other hyponyms of renter include leaseholder, lessee, lodger, roomer.

renter (noun)	boarder (noun)
someone who pays rent to use land or a building or a car that is owned by someone else	a tenant in someone's house
an owner of property who receives payment for its use by another person	a pupil who lives at school during term time
	someone who forces their way aboard ship