chalk [OE] Old English cealc, the forerunner of chalk, also meant ‘lime’. It came from Latin calx ‘lime’, which is also the source of calcium [E19th]. When we say by a long chalk [M19th], meaning ‘to a great degree, by far’ (and not by a long chalk, ‘not at all’), the ‘long chalk’ refers to the length of a line of chalk marks or tallies drawn on a blackboard. This may originally have been in the context of a pub game, where points scored were marked up on the blackboard, or perhaps in the classroom, with a teacher chalking up pupils’ marks for schoolwork. In either case, a long line of chalk marks against your name would mean you were a long way ahead of the others.