mid-14c., "serpent's tongue" (thought to be a stinging organ), later "sharp extension of a metal blade" (1680s), from Old Norse tangi "spit of land, pointed metal tool," perhaps related to tunga "tongue" (see tongue). Figurative sense of "a sharp taste" is first recorded mid-15c.; that of "suggestion, trace" is from 1590s. The fish (1734) so called for their spines.
reignreign name of the Chinese emperor who overthrew the Xia dynasty (c. 2070-c. 1600 BC) and founded the Shang, the first historical dynasty ( c. 1600-1046 BC, though the dating of the Shang-and hence also of the Tang emperor's founding of it-have long been the subject of much debate).