The cavity of the mouth, especially the part of the mouth behind the gums and teeth that is bounded above by the hard and soft palates and below by the tongue and by the mucous membrane connecting it with the inner part of the mandible.
The hollow on the lower surface of the head from which the proboscis protrudes.
The part of the alimentary canal and respiratory tract that extends from the back of the mouth and nasal cavity to the larynx and esophagus.
The part of the alimentary canal immediately behind the mouth in invertebrates that may be thickened and muscular, eversible and toothed, or adapted as a suctorial organ.