blackboard
black‧board /ˈblækbɔːd $ -bɔːrd/
noun [countable]

a board with a dark smooth surface, used in schools for writing on with chalk
⇨ whiteboard
black‧board /ˈblækbɔːd $ -bɔːrd/
noun [countable]
a board with a dark smooth surface, used in schools for writing on with chalk
⇨ whiteboard