The Collaborative International Dictionary of English v.0.48:

Hexastyle \Hex"a*style\, a. [Gr. ? with six columns; "e`x six +
   column: cf. F. hexastyle.] (Arch.)
   Having six columns in front; -- said of a portico or temple.
   -- n. A hexastyle portico or temple.
   [1913 Webster]