FIS'TULA, n. [L.; Eng. whistle.]

1. Properly, a pipe; a wind instrument of music, originally a reed.

2. A surgery, a deep, narrow and callous ulcer, generally arising from abscesses. It differs from a sinus, in being callous.

Fistula lachrymalis, a fistula of the lachrymal sac, a disorder accompanied with a flowing of tears.