board vs boarder

board and boarder both are nouns.

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

board (noun)	boarder (noun)
a flat piece of material designed for a special purpose	a tenant in someone's house
a table at which meals are served	a pupil who lives at school during term time
electrical device consisting of a flat insulated surface that contains switches and dials and meters for controlling other electrical devices	someone who forces their way aboard ship
a vertical surface on which information can be displayed to public view
a printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities
a flat portable surface (usually rectangular) designed for board games
food or meals in general
a committee having supervisory powers
a stout length of sawn timber; made in a wide variety of sizes and used for many purposes

board (verb)	boarder (verb)
provide food and lodging (for)
lodge and take meals (at)
get on board of (trains, buses, ships, aircraft, etc.)
live and take one's meals at or in