Snitched (6)
I believe the answer is:
ratted
'snitched' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ratted that I've seen before include "Broke promise in treacherous or rodent style" , "Deserted the side, rodent-like" , "Betrayed or informed, the rodent" , "Deserted; very drunk" , "Betrayed like a rodent" .)