Ornament at the top of a spire or column (6)
I believe the answer is:
finial
'ornament at the top of a spire or column' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for finial that I've seen before include "highest decoration!" , "Roof ornament" , "Ornament on the top of a building" , "topmost decoration" , "Crowning touch" .)