1. in zoology, a common passage for faecal, urinary, and reproductive discharge in most lower vertebrates. 2. in mammalian embryology, the terminal end of the hindgut before division into rectum, bladder, and genital primordia. 3. in pathology, an opening in the involucrum of a necrosed bone.
Coagulation is usually irreversible.
3. in surgery, the disruption of tissue by physical means to form an amorphous residuum, as in electrocoagulation and photocoagulation.