Source : Webster's Revised Unabridged Dictionary (1913)

Torus \To"rus\, n.; pl. {Tori}. [L., a round, swelling, or
   bulging place, an elevation. Cf. 3d {Tore}.]
   1. (Arch.) A lage molding used in the bases of columns. Its
      profile is semicircular. See Illust. of {Molding.}
      --Brande&C.

   2. (Zo["o]l.)One of the ventral parapodia of tubicolous
      annelids. It usually has the form of an oblong thickening
      or elevation of the integument with rows of uncini or
      hooks along the center. See Illust. under {Tubicol[ae]}.

   3. (Bot.) The receptacle, or part of the flower on which the
      carpels stand.

   4. (Geom.) See 3d {Tore}, 2.

Source : WordNet®

torus
     n 1: a ring-shaped surface generated by rotating a circle around
          an axis that does not intersect the circle [syn: {toroid}]
     2: commonly the lowest molding at the base of a column [syn: {tore}]
     [also: {tori} (pl)]