Changing room's bare after removing a hat (8)
I believe the answer is:
sombrero
'hat' is the definition.
(I know that sombrero is a type of hat)
'changing room's bare after removing a' is the wordplay.
'changing' is an anagram indicator.
'after removing' indicates named letters should be taken away.
'rooms'+'bare'='roomsbare'
'roomsbare' with 'a' taken away is 'roomsbre'.
'roomsbre' anagrammed gives 'SOMBRERO'.
(Other definitions for sombrero that I've seen before include "a Mexican's overheads" , "headgear from Mexico" , "Straw hat with very wide brim from Mexico" , "It may be felt" , "headgear in parts of US" .)