Lewis & Short

bĭfŏris, e (bĭfŏrus, a, um, Vitr. 4, 6 fin.), adj. [bis-foris].

  1. I. Having two doors or folding-doors: valvae, Ov. M. 2, 4: fenestrae, id. P. 3, 3, 5.
  2. II. Having two openings or holes, double: via (narium), App. Dogm. Plat. 1.
    Poet.: ubi assuetis biforem dat tibia cantum, Verg. A. 9, 618 (bisonum, imparem, Serv.); Aus. Cent. Nupt. 27: biforis tumultus, Stat. Th. 4, 668.