boarder

[bawr-der, bohr-] /ˈbɔr dər, ˈboʊr-/
noun
1.
a person, especially a lodger, who is supplied with regular meals.
2.
a member of a boarding party.
Origin
1520-30; board + -er1
Can be confused
boarder, border.
British Dictionary definitions for boarder

boarder

/ˈbɔːdə/
noun
1.
(Brit) a pupil who lives at school during term time
2.
(US) a child who lives away from its parents and is cared for by a person or organization receiving payment
3.
another word for lodger
4.
a person who boards a ship, esp one who forces his way aboard in an attack: stand by to repel boarders
5.
(informal) a person who takes part in sailboarding or snowboarding
Word Origin and History for boarder
n.

1520s, "one who has food and/or lodging at the house of another," agent noun from board (v.), in this sense from board (n.1) in the "food" sense; meaning "one who boards (an enemy's) ships" is from 1769, from a verbal sense derived from board (n.2).