Dividing the team's hilarious (4-9)
I believe the answer is:
side-splitting
'hilarious' is the definition.
(I've seen this before)
'dividing the team's' is the wordplay.
I cannot quite see how this works, but
'dividing' could be 'splitting' (splitting is a kind of dividing) and 'splitting' is found within the answer.
'team' could be 'side' (both can mean a sports team) and 'side' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for side-splitting that I've seen before include "Producing great mirth" , "Hilarious" , "Extremely funny" .)