To do something chop-chop is to do it smartly, briskly, with alacrity. Its origin is early 19th century from Cantonese Pidgin English chop, meaning quick. In point of fact, the Cantonese for quick is kwai, which is a far cry from chop. The reason for this is entirely due to British sailors who introduced chop-chop into Cantonese Pidgin. Since the 1600s, chop or chop up has been a nautical term for a sudden shift or change in wind or sea direction, in the same sense as a choppy sea. Sailors would say, for example, “The wind is chopping up westerly” meaning a sudden wind shift from the west. It is this sense of sudden-ness that was used when sailors would say chop-chop to Chinese dockworkers to get them to hurry up. The Chinese soon adopted the expression themselves as part of Cantonese Pidgin. Chopstick or chopsticks come from the same etymological root but appears much earlier in English than chop-chop, from 1699 according to the OED, and chopsticks were so-called because of the speed at which the Chinese used them.