Jaw  —n. 1 a upper or lower bony structure in vertebrates containing the teeth. B corresponding parts of certain invertebrates. 2 a (in pl.) The mouth with its bones and teeth. B narrow mouth of a valley, channel, etc. C gripping parts of a tool etc. D grip (jaws of death). 3 colloq. Tedious talk (hold your jaw). —v. Colloq. Speak, esp. At tedious length. [french]