Tower of a mosque (7)
I believe the answer is:
minaret
'tower of a mosque' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for minaret that I've seen before include "Raiment worn on mosque tower" , "Tower from which muezzin calls Muslims to prayer" , "Slender mosque tower" , "Appropriate raiment for mosque tower" , "Muezzin's tower" .)