Source : Webster's Revised Unabridged Dictionary (1913)

Rhomb \Rhomb\, n. [L. rhombus, Gr. ??? rhomb, a spinning top,
   magic wheel, fr. ??? to turn or whirl round, perhaps akin to
   E. wrench: cf. F. rhombe. Cf. {Rhombus}, {Rhumb}.]
   1. (Geom.) An equilateral parallelogram, or quadrilateral
      figure whose sides are equal and the opposite sides
      parallel. The angles may be unequal, two being obtuse and
      two acute, as in the cut, or the angles may be equal, in
      which case it is usually called a square.

Source : WordNet®

rhomb
     n : a parallelogram with four equal sides; an oblique-angled
         equilateral parallelogram [syn: {rhombus}]