term given by Vitruvius to the intercolumniation between the columns of a temple, when this was equal to 11/2 diameters.[48]
having closely spaced columns
• (n.) A pycnostyle colonnade. • (a.) See under Intercolumniation.
Pyc'no·style adjective [ Greek ... with the pillars close together; ... close + ... a column, pillar: confer French pycnostyle .] (Anc. Arch.) See under Intercolumniation . - noun A pycnostyle colonnade. 
Pycnostyle is an arrangement of columns in Greek and Roman architecture, in which the intercolumniations are equal to one diameter and a half of the lower part of the shaft.
having an intercolumniation of 1 diameters. See illus. under