lick one's chops, to

Fig. to show one's eagerness to do something, especially to eat something. We could tell from the way the boys were licking their chops that they really wanted a turn at riding the motorcycle. Fred started licking his chops when he smelled the turkey roasting in the oven.

Also, lick one's lips. Anticipate with great pleasure. For example, The kids were licking their chops as Mother described the family vacation plans, or I couldn't help but lick my lips when she talked about the menu. Both expressions allude to anticipating a tasty morsel of food. The second is the older, dating from about 1500 and used interchangeably with lick one's fingers, now seldom heard. The first also served as 1930s jazz slang for warming up, chops meaning "the jaw or mouth" (a usage dating from the 1300s).

To anticipate delightedly.

To anticipate something with obvious pleasure. The word chops (or chaps) has meant the jaws or mouth since about 1350, usually referring to the lower jaw of animals. This meaning survives in the current cliché, as well as in musicians’ slang for the embouchure of wind instruments. In jazz slang of the 1930s and 1940s, licking one’s chops meant warming up before a performance. In jazz parlance chops also came to mean ability or skill, a usage from the 1960s.