/chad/ n. 1. The perforated edge strips on printer paper, after
they have been separated from the printed portion. Also called
. 2. obs. The confetti-like paper bits punched
out of cards or paper tape; this was also called `chaff', `computer
confetti', and `keypunch droppings'.
Historical note One correspondent believes `chad' (sense 2)
derives from the Chadless keypunch (named for its inventor), which
cut little u-shaped tabs in the card to make a hole when the tab
folded back, rather than punching out a circle/rectangle; it was
clear that if the Chadless keypunch didn't make them, then the
stuff that other keypunches made had to be `chad'.