The oral cavity, bound by the cheeks of the face, the palate, and the flesh of the mandible, opening onto the mouth and the fauces, and containing the teeth, tongue, gums, and other structures.
The first part of the stomodaeum, lying just within the mouth; its dilator muscles arising on the clypeus, and inserted before the frontal ganglion and its connectives.
The mouth; muzzle; face, especially the lower part (mouth and chin).