n. A building (especially a portico) that has four columns
the GNU version of the Collaborative International Dictionary of English
adj. Having four columns in front; -- said of a temple, portico, or colonnade.
The Century Dictionary and Cyclopedia
In ancient architecture and kindred styles, having or consisting of four columns.
n. A structure having four pillars; a combination or group of four pillars.
Word Usage
"A third method of designating or distinguishing the temples is by the number of columns in front, thus temples are called tetrastyle, hexastyle, octastyle, that is having five, six, or eight columns."