The Collaborative International Dictionary of English v.0.48:

Zikkurat \Zik"ku*rat\, n.
   A temple tower of the Babylonians or Assyrians, consisting of
   a lofty pyramidal structure, built in successive stages, with
   outside staircases, and a shrine at the top; -- called also
   ziggurat.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Ziggurat \Zig"gu*rat\, n.
   A temple tower of the Babylonians or Assyrians, consisting of
   a lofty pyramidal structure, built in successive stages, with
   outside staircases, and a shrine at the top; -- called also
   zikkurat.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

ziggurat
    n 1: a rectangular tiered temple or terraced mound erected by
         the ancient Assyrians and Babylonians [syn: ziggurat,
         zikkurat, zikurat]