Bitch lip is a phrase in which a person packing a lip (doing smokeless tobacco) takes a tiny pinch that is almost unrecognizable as an actual lip. Comparatively, a bitch lip is the opposite of a "mouthpiece" or a "upper and lower mouthpiece". In the former, said person dipping packs the lip throughout the bottom teeth all the way from the front to the molars in the back; in the latter, the idea is the same, however both upper and lower teeth are packed (the almighty grail of dipping).