The Collaborative International Dictionary of English v.0.48:

Cyclostylar \Cy`clo*sty"lar\ (s?`kl?-st?"?r), a. [Cyclo- + Gr.
   sty^los column.]
   Relating to a structure composed of a circular range of
   columns, without a core or building within. --Weale.
   [1913 Webster]