1911 Encyclopædia Britannica/Tattoo

TATTOO, a signal given by beat of drum and call of bugle at nightfall for soldiers to go to quarters when in garrison or to tents when in the field. The earlier word is taploo or laptow, and was borrowed from Du. laploe; the phrase de taploe slaan, to close the taps, and the parallel Ger. Zapfenstreich, literally “tap-stroke” (Zapf, a tap of a cask), show that it meant originally a signal that the “taps” or public-houses were closed for the night.