Source : Webster's Revised Unabridged Dictionary (1913)

Prostyle \Pro"style\, a. [L. prostylus, Gr. ?; ? before + ?
   pillar, column: cf. F. prostyle.] (Arch.)
   Having columns in front. -- n. A prostyle portico or
   building.

Source : WordNet®

prostyle
     adj : marked by columniation having free columns in a portico only
           across the opening to the structure [syn: {pseudoprostyle}]