blackboard
black·board
noun
Origin
From black + board, because such surfaces were once typically made of black slate.
Related words
Word family
Broader terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.