口腔

oral cavity

mouth / classifier for things with mouths (people, domestic animals, cannons, wells etc) / classifier for bites or mouthfuls

cavity of body / barrel (e.g. engine cylinder) / compartment / tune / accent of speech

(bound form) cavity / tune / accent (in one's speech) / (old) (classifier for carcasses of slaughtered livestock)

stomatitis / ulceration of oral cavity / inflammation of the mucous lining of the mouth