Frightens the cat (5)
I believe the answer is:
shoos
'frightens' is the definition.
Although both the answer and definition are verbs in their -s form, I don't see how they can define each other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for shoos that I've seen before include "Drives away audibly" , "Scares off" .)