Bridle in which there’s an animal hair (7)
I believe the answer is:
bristle
This might be a double definition.
'bridle in which there's an animal' is the first definition.
'bristle' can be an answer for 'bridle' (thesaurus). I am not sure about the rest of the definition.
'hair' is the second definition.
(bristle is a kind of hair)
Can you help me to learn more?
(Other definitions for bristle that I've seen before include "rise up" , "Stiff fibre" , "Display anger - stubble" , "React angrily" , "Get angry" .)