Antrum

Based on Greek antron meaning “cave,” a cavity or chamber in the body, often within bone.

Any cavity inside the body, especially one in bone.

Section of the stomach that terminates at the pylorus.

A cavity, especially a cavity in a bone. The mastoid (or tympanic) antrum is the space connecting the air cells of the ‘mastoid process with the chamber of the inner ear.

Antrum means a natural hollow or cavity. The maxillary antrum is now known as the maxillary sinus. The mastoid antrum is situated in the mastoid process, the mass of bone felt behind the ear. It may become the seat of an abscess in cases of suppuration of the middle ear. The pyloric antrum is the part of the stomach immediately preceding the pylorus.

Any nearly closed cavity or chamber, especially in a bone.