Meaning

noun a soft whitish calcite

noun a pure flat white with little reflectance

noun an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant

originEtymology tree Pre-Greekbor.? Ancient Greek χᾰ́λῐξ (khắlĭx)bor.? substratebor.? Latin calxbor. Proto-West Germanic *kalk Old English ċealc Middle English chalk English chalk Inherited from Middle English chalk, chalke, from Old English ċealc, from Proto-West Germanic *kalk, borrowed from Latin calx (“limestone”), again borrowed from Ancient Greek χάλιξ (khálix, “pebble”). Doublet of calx and cauk.

Etymology from Wiktionary, CC BY-SA 3.0