Diver's garment (7)
(Other definitions for wetsuit that I've seen before include "Garment worn by some skin-divers" , "Garment worn by a diver" , "diving gear" .)
'diver's garment' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for wet suit that I've seen before include "Diver's rubber gear" , "Sportswear" , "Garment worn by a diver" , "Diving attire" , "Garment worn by divers etc" .)