the division between skin that has darkened or tanned from exposure to sun and skin that has not been exposed to sun

(idiomatic) The tan line left by clothing, especially by a short-sleeved shirt.

Any of various breeds of dog having black and tan colouring. / (US slang, now historical) A bar, nightclub etc. which had both black and white customers, especially one that featured black entertainers.

plural of tanning bed

A device emitting ultraviolet radiation used to produce a cosmetic suntan.

plural of tan line

Chinese New Year

The red sage or Chinese sage (Salvia miltiorrhiza)

(obsolete) A large vat in which wort ferments as part of brewing.

A Chinese gambling game in which coins or other small objects are placed upon a table, usually under a cup, and the players bet as to what remainder will be left when the sum of the counters is divided by four.