• (a.) Having five columns in front; -- said of a temple or portico in classical architecture. • (n.) A portico having five columns.
Pen'ta·style adjective [ Penta- + Greek ... a pillar.] (Architecture) Having five columns in front; - - said of a temple or portico in classical architecture. -- noun A portico having five columns. 
In architecture the term pentastyle describes a structure having five columns in front. It is usually said of a temple or portico in classical architecture.