Definition of "lower jaw" []

• The part of the face below the mouth; the jaw. (noun)
• Specifically, the bone therein; the mandible of humans and other vertebrates that, with the cranium, composes the skull. (noun)

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• "The Ethiopian race includes the inhabitants of Africa except the Caucasian Africans in the north; the skull is dolichocephalic, the forehead full, the cheek-bones prominent, the nostrils wide, the alveolar arch narrow and prominent, the jaws prognathous, and the lower jaw large and strong."
• "He pulled the cigarette from his mouth, ground it out on the tabletop, and leaned forward, hands warped into claws, lower jaw extended prognathically."
• "At the same time it rapidly moved its lower jaw or lips in a spasmodic manner, the teeth being exposed; but the noise produced was hardly more distinct than that which we sometimes call silent laughter."