Even risk to cat, being knocked over (4-2)
I believe the answer is:
toss-up
'even risk' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'to cat being knocked over' is the wordplay.
'cat' becomes 'puss' (puss is a kind of cat).
'being knocked over' shows that the letters should be reversed in order.
'puss' backwards is 'ssup'.
'to'+'ssup'='TOSS-UP'
Can you help me to learn more?
(Other definitions for toss-up that I've seen before include "Use of a coin to choose" , "It helps you pick" , "Fifty-fifty chance" , "Flip of a coin" .)