fistula

noun

1. An abnormal connection or passageway between organs or vessels that normally do not connect.

   “communicating fistula”

   “blind fistula”

   “Small fistulæ are to be closed bilaterally in an antero-posterior line[…]”

   “There are several reasons why a manual on this disease should be a part of the veterinary literature of the day, the chief one being that fistula of the withers is a very prevalent disease of horses and thus exacts a big toll from the horse industry.”

   “Fistulas are abnormal communications between two epithelialized surfaces. The causes of enterocutaneous fistulas can be remembered using the mnemonic FRIEND: Foreign body, Radiation, Inflammation/Infection/Inflammatory bowel disease, Epithelialization, Neoplasm, and Distal obstruction. Fifteen to twenty-five percent of enterocutaneous fistulas arise spontaneously as in, for example, Crohn’s disease or cancer.”

2. (rare)A tube, a pipe, or a hole.
3. (historical)The tube through which the wine of the Eucharist was once sucked from the chalice in certain ceremonies (such as papal Masses).