Stop cat spending month inside box (3,3)
I believe the answer is:
cut off
'stop' is the definition.
(cutting off is a kind of stopping)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for cut off that I've seen before include "Power interrupter" , "Limit (3-3); sever" , "Fixed limit" , "Block" , "Sever, prevent from continuing" .)