blackboard

UK: /ˈblækbɔː^rd/ US: /ˈblækˌbɔrd/ ,(blak′bôrd′, -bōrd′)

WordReference Random House Learner's Dictionary of American English © 2025

black•board /ˈblækˌbɔrd/   n. [countable]

1. a sheet of smooth material, esp. dark slate, used for writing with chalk:
   The students went up to the blackboard and wrote their examination sentences.

WordReference Random House Unabridged Dictionary of American English © 2025

black•board  (blak′bôrd′, -bōrd′), n. 

1. a sheet of smooth, hard material, esp. dark slate, used in schools, lecture rooms, etc., for writing or drawing on with chalk. Also called chalkboard. Cf. greenboard.

• black + board 1815–25

Collins Concise English Dictionary © HarperCollins Publishers::

blackboard / ˈblækˌbɔːd/ noun

1. a hard or rigid surface made of a smooth usually dark substance, used for writing or drawing on with chalk, esp in teaching