noun
(pathology) A gap or space between two adjacent teeth, especially the upper front incisors (in humans).
(zoology, anatomy) A gap between teeth of different types, e.g. incisors and molars, which is a feature of some rodents and ungulates.
(pathology) Any abnormal space, fissure, or cleft in an organ or other part of the body.
(cytology) The modified protoplasm at the equator of a cell, existing before mitotic division.