Run in rain (4)
I believe the answer is:
pelt
This clue is a double definition.
'run' is the first definition.
(thesaurus)
'rain' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for pelt that I've seen before include "Animal skin with fur still on it" , "fall heavily" , "what rain might do" , "Subject to bombardment" , "Raw hide" .)