blackboard

/ˈblækboɹd/

IPA: /B L AE1 K B AO0 R D/

noun
  1. 1

    A large flat surface, finished with black slate or a similar material, that can be written upon with chalk and subsequently erased; a chalkboard.

verb
  1. 1

    To use a blackboard to assist in an informal discussion.

Source: https://en.wiktionary.org/wiki/blackboard