1. Occurring naturally and normally in a certain type of tissue or in a specific structure of the body.
2. Sometimes used to denote a neoplasm derived from cells that occur normally at that site, e.g., a squamous cell carcinoma in the upper esophagus.
3. In transplantation, referring to a graft in which the donor and recipient areas are in the same individual.
Origin
[auto- + G. logos, relation]