before 1000;1920-25for def 2;Middle Englishtannen to make hide into leather, late Old English*tannian (in past participle getanned; cf. tanner1) < Medieval Latintannāre, derivative of tannum oak bark, tanbark < Germanic; compare Old High Germantanna oak, fir, akin to Dutchden fir
late O.E. tannian "to convert hide into leather" (by steeping it in tannin), from M.L. tannare "tan, dye, a tawny color" (c.900), from tannum "crushed oak bark," used in tanning leather, probably from a Celtic source (e.g. Breton tann "oak tree"). The meaning "make brown by exposure to the sun" first recorded 1530. To tan (someone's) hide in the figurative sense is from 1670. The adj. tan "of the color of tanned leather" is recorded from 1665; the noun sense of "bronze color imparted to skin by exposure to sun" is from 1749; as a simple name for a brownish color, in any context, it is recorded from 1888.
have someone's hide. Spank or beat someone, as in Dad said he'd tan Billy's hide if he caught him smoking, or I'll have your hide if you take something without paying for it. This term uses hide in the sense of “skin.” The allusion in the first expression is to a spanking that will change one's skin just as chemicals tan animal hide (convert it into leather).
[ Second half of 1600s