Meaning of “board” - Learner’s Dictionary

board

noun uk us /bɔːd/
WOOD [ C ]

a long, thin, flat piece of wood:

He nailed some boards across the broken window.
SURFACE [ C ]

B1 a flat piece of wood, plastic, etc used for a particular purpose:

an ironing board
a chopping board
INFORMATION [ C ]

A2 a piece of wood, plastic, etc on a wall, where information can be put:

Have you seen the poster on the board?
SCHOOL ROOM [ C ]

A1 a surface on the wall of a school room that the teacher writes on:

Copy down the sentences from the board.
GAMES [ C ]

A2 a piece of wood, cardboard, etc for playing games on:

a chess board
ORGANIZATION [ group ]
on board

B1 on a boat, train, aircraft, etc

MEALS [ U ]

B2 meals that are provided when you stay in a hotel:

bed and board
How much is a single room with full board (= all meals)?

(Definition of “board noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)