IPA: /ˈtʃɔːk.bɔːrd/
KK: /ˈtʃɔkˌbɔrd/
A flat, smooth surface, often black or green, used for writing on with chalk, commonly found in classrooms.
The teacher wrote the math problems on the chalkboard for the students to see.
Chalkboard is formed from "chalk" (from Old English *cealc*, meaning a white, soft stone used for writing) and "board" (from Old English *bord*, meaning a flat piece of wood or other material). The word "chalkboard" refers to a flat surface made for writing with chalk.
Think of 'chalk' as the white writing material and 'board' as the flat surface — together, they create a surface for writing with chalk.