Blackboard
A blackboard (also known as a chalkboard) is a reusable writing surface on which text or drawings are made with sticks of calcium sulfate or calcium carbonate, known, when used for this purpose, as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone.
Chalkboard (noun)
A slate or enamel board for writing on with chalk; a predecessor to a whiteboard.
Blackboard (noun)
A large flat surface, finished with black slate or a similar material, that can be written upon with chalk and subsequently erased; a chalkboard.
Blackboard (verb)
To use a blackboard to assist in an informal discussion.
Chalkboard (noun)
another term for blackboard
Blackboard (noun)
a large board with a smooth dark surface attached to a wall or supported on an easel and used by teachers in schools for writing on with chalk.