Definition of pentastyle in US English:

pentastyle

noun

Architecture
rare
  • A building or portico with five columns or five rows of columns.

adjective

Architecture
rare
  • Of a portico, etc.: five-columned.

Origin

Early 18th century; earliest use found in Ephraim Chambers (?1680–1740), encyclopaedist. From penta- + ancient Greek στῦλος pillar. Compare French pentastyle.

Pronunciation

pentastyle

/ˈpɛntəstʌɪl/