The Collaborative International Dictionary of English v.0.48:
Prostyle \Pro"style\, a. [L. prostylus, Gr. ?; ? before + ? pillar, column: cf. F. prostyle.] (Arch.) Having columns in front. -- n. A prostyle portico or building. [1913 Webster]WordNet (r) 3.0 (2006):
prostyle adj 1: marked by columniation having free columns in a portico only across the opening to the structure [syn: prostyle, pseudoprostyle]