Controls animal in bad weather, they say (4)
I believe the answer is:
rein
'controls animal' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'bad weather they say' is the wordplay.
'bad weather' becomes 'rain' (rain is an example of bad weather).
'they say' shows a homophone (sound like).
'rain' is a homophone of 'REIN'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for rein that I've seen before include "Slow-up" , "(Horse's) guiding strap" , "Check; control" , "Restraint; strap attached to horse's bit" , "given free to experienced riders?" .)