Diving gear (5)
I believe the answer is:
scuba
'diving gear' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scuba that I've seen before include "Skin-diver's device" , "Apparatus for divers" , "Device that lets divers breathe under water" , "Skin-diving apparatus" , "Diving equipment" .)