Lewis & Short

fistŭlāris, e, adj. [fistula] (post-class.).

  1. I. (Acc. to fistula, II. A. 2. a.) Like a shepherd’s pipe: versus, which gradually increase by a syllable, Diom. p. 498 P.
  2. II. (Acc. to fistula, II. B.) Of or for a fistula: medicamentum, Veg. Vet. 2, 13.