Angler's boot (5)
I believe the answer is:
wader
'angler's boot' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for wader that I've seen before include "High waterproof boot" , "Bird such as a sandpiper or plover" , "Heron, say" , "crane, perhaps" , "Type of long-legged bird" .)