Canal hat (6)
I believe the answer is:
panama
I believe this is a double definition.
'canal' is the first definition.
'hat' is the second definition.
(I know that Panama is a type of hat)
(Other definitions for panama that I've seen before include "Great American canal or tropical hat" , "American canal or kind of hat" , "Central American state" , "Criticise" , "Man's hat" .)