Sound from a contented cat (4)
I believe the answer is:
purr
'sound from a contented cat' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for purr that I've seen before include "Appreciative feline sound" , "Sound of a happy mog" , "Make low, contented sound" , "Sound of feline content" , "content? I might" .)