BACKBOARD
backboard
(noun) a board used to support the back of someone or something
backboard, basketball backboard
(noun) a raised vertical board with basket attached; used to play basketball; “he banked the shot off the backboard”
Source: WordNet® 3.1
Etymology 1
Noun
backboard (plural backboards)
(basketball) The flat vertical surface to which the basket is attached.
(tennis) A flat vertical wall with the image of a tennis net drawn or painted on it. Designed to practice hitting against such that the ball bounces back.
(medicine, first aid) A spine board.
A board placed at the back of a cart, boat, etc.
Etymology 2
Noun
backboard (usually uncountable, plural backboards)
(nautical) The port or larboard side of a ship
Synonyms: larboard, port
Source: Wiktionary
Back"board`, n. Etym: [2nd back, n. + board.]
1. A board which supports the back wen one is sitting;
Note: specifically, the board athwart the after part of a boat.
2. A board serving as the back part of anything, as of a wagon.
3. A thin stuff used for the backs of framed pictures, mirrors, etc.
4. A board attached to the rim of a water wheel to prevent the water
from running off the floats or paddies into the interior of the
wheel. W. Nicholson.
5. A board worn across the back to give erectness to the figure.
Thackeray.
Source: Webster’s Unabridged Dictionary 1913 Edition