tan: [OE] Tan was borrowed into late Old English from the medieval Latin verb tannāre. This was derived from tannum ‘oak bark’ (oak bark is used in tanning leather), which itself was probably a loan-word from Gaulish tanno- ‘oak’. The French noun tan ‘tan’ came ultimately from the same Latin source. From it was derived tanin, acquired by English as tannin [19]; and its immediate Old French predecessor formed the basis of an adjective tané ‘tancoloured, dark’, whose Anglo-Norman version tauné gave English tawny [14]. => tannin, tawny
