Headgear but not the topper in town (5)
I believe the answer is:
urban
'town' is the definition.
(urban means relating to a town or city)
'headgear but not the topper in' is the wordplay.
'headgear' becomes 'turban' (turban is a kind of headgear).
'but not the topper in' means to remove the first letter (the top letter is removed).
'turban' with its first letter taken away is 'URBAN'.
(Other definitions for urban that I've seen before include "Citified" , "Of towns or cities" , "One of eight popes" , "Situated in city or town" , "Relating to a city/town" .)