Type of gun: transport it to Macau (9)
I believe the answer is:
automatic
'type of gun' is the definition.
'transport it to macau' is the wordplay.
'transport' indicates an anagram (each letter must be moved or 'transported').
'it'+'to'+'macau'='ittomacau'
'ittomacau' with letters rearranged gives 'AUTOMATIC'.
(Other definitions for automatic that I've seen before include "by machine" , "Type of gun or car" , "Without volition or conscious control" , "Occurring as a matter of course" , "Reflex" .)