Tattoo

Definition:

(n.) A beat of drum, or sound of a trumpet or bugle, at night, giving notice to soldiers to retreat, or to repair to their quarters in garrison, or to their tents in camp.
(v. t.) To color, as the flesh, by pricking in coloring matter, so as to form marks or figures which can not be washed out.
(n.) An indelible mark or figure made by puncturing the skin and introducing some pigment into the punctures; -- a mode of ornamentation practiced by various barbarous races, both in ancient and modern times, and also by some among civilized nations, especially by sailors.

Compare tattoo with other words:

backpiece vs. tattoo