Other forms: chalks
Chalk is the soft white stick teachers once used on dark boards. A stick of chalk, chalk dust, write it in chalk.
It is also the soft white rock the sticks were originally made from — the chalk of the South Downs and the white cliffs of Dover, formed from the shells of countless tiny sea creatures. Climbers and gymnasts use chalk on their hands for grip. Note chalk and cheese, the British phrase for two things utterly unalike; chalk it up to experience; and by a long chalk, meaning by a wide margin, from scoring games in chalk.
1nounchalkA soft white stick used for writing on boards.
“There was chalk dust on his sleeve every day for thirty years.”
2nounrockThe soft white rock it is made from.
“The whole ridge is chalk and drains in minutes.”
chalk is a soft white substance.
Latin calx meant limestone, and it came into Old English early, before the Norman conquest. The same calx gives calcium and calculate — from the pebbles used for counting.
Middle English
chalk
English, today
chalk
From Middle English chalk. Middle English chalk,chalke, from Old English ċealc, from Proto-West Germanic kalk, borrowed from Latin calx (“limestone”), again borrowed from Ancient Greek χάλιξ (“pebble”). a doublet of calx and cauk.
Etymology from Wiktionary, CC BY-SA