Akademik

chalk
n. & v.
—n.
1 a white soft earthy limestone (calcium carbonate) formed from the skeletal remains of sea creatures.
2 a a similar substance (calcium sulphate), sometimes coloured, used for writing or drawing. b a piece of this (a box of chalks).
3 a series of strata consisting mainly of chalk.
4 = French chalk.
—v.tr.
1 rub, mark, draw, or write with chalk.
2 (foll. by up) a write or record with chalk. b register (a success etc.). c charge (to an account).
Phrases and idioms:
as different as chalk and (or from) cheese fundamentally different. by a long chalk Brit. by far (from the use of chalk to mark the score in games). chalk and talk traditional teaching (employing blackboard, chalk, and interlocution). chalk out sketch or plan a thing to be accomplished. chalk-pit a quarry in which chalk is dug. chalk-stone a concretion of urates like chalk in tissues and joints esp. of hands and feet. chalk-stripe a pattern of thin white stripes on a dark background. chalk-striped having chalk-stripes.
Etymology: OE cealc ult. f. WG f. L CALX

Useful english dictionary. 2012.