This water's wrecked garment (10)
I believe the answer is:
sweatshirt
'garment' is the definition.
(sweatshirt is a kind of garment)
'this water's wrecked' is the wordplay.
'wrecked' indicates an anagram.
'this'+'waters'='thiswaters'
'thiswaters' with letters rearranged gives 'SWEATSHIRT'.
(Other definitions for sweatshirt that I've seen before include "Long-sleeved, knitted cotton sweater" , "Long-sleeved top worn by athletes" , "casual gear" , "leisurewear" .)