Greek column style (5)
I believe the answer is:
doric
'greek column style' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for doric that I've seen before include "Classical building style" , "A classical style of architecture with fluted columns" , "Style of column" , "One classical order in architecture" , "In a classical Greek style of architecture" .)