Lewis & Short

bĭpĕdālis, e, adj. [bis-pes],

  1. I. two feet long, broad, or thick (class. in prose and poetry): fenestrae, Cato, R. R. 14, 2: trabes, two feet thick, Caes. B. G. 4, 17: materia, id. B. C. 2, 10: sol huic (Epicuro) bipedalis fortasse videtur, * Cic. Fin. 1, 6, 20: adulescentulus bipedali minor, * Suet. Aug. 43: tegulae, Vitr. 7, 1 fin.: modulus, Hor. S. 2, 3, 309: hiatus, Plin. 16, 12, 23, § 57: latitudo, Col. 8, 3, 7.
  2. II. Subst.: bĭpĕdāle, is, n., a tile or flag-stone two feet long, Inscr. Fabr. p. 500, 39.