Webster's English Dictionary

tan

1. tan \'tan\ vb or tanned;  or tan.ning [ME tannen, fr. MF tanner, fr. ML 
   tannare, fr. tanum, (Xtannum tanbark 1: to convert (hide) into leather by 
   treatment with an infusion of tannin- rich bark or other agent of similar 
   effect 2: to make brown or tan esp. by exposure to the sun  3: THRASH, WHIP 
    : to get or become tanned 
2. tan n [F, fr. OF, fr. ML tanum] 1: TANBARK  2: a tanning material or its 
   active agent (as tannin)  3: a brown color imparted to the skin by exposure 
   to the sun or weather  4: a variable color averaging a light yellowish 
   brown 
3. tan aj 1: of, relating to, or used for tan or tanning  2: of the color 
   tan