either of the two bony structures that form the framework of the mouth; especially the lower jaw (mandible) or the upper jaw (maxilla).

口を形作る骨・あご（下あご＝下顎、上あご＝上顎）

the part of a tool or device that grips or holds (the 'jaws' of a clamp, vice, or animal's mouth).

工具などの『挟む部分』（例：クランプの顎・挟み部）

to talk at length in an informal or idle way; to chat.

長時間くだけて話す・おしゃべりをする

to grip or hold between the jaws (literal use, e.g., machine parts or animals).

（顎や工具などで）つかむ、はさむ