The side part of an organ or a passage in the body.
Confining, limiting, or enclosing part, especially a broad surface, as the wall of the abdominal cavity.
The limiting or surrounding substance or material of a vessel or cavity such as an artery, vein, chest, or bladder. In dentistry, it may refer to specific boundaries of a cavity preparation or its location within the tooth, for example, cavity walls: buccal, lingual, mesial, distal, pulpal, coronal, axial, cervical, facial, incisal, gingival, or enamel.