Couple from Petworth (3)
I believe the answer is:
two
'couple' is the definition.
(a couple can mean two of something)
'from petworth' is the wordplay.
'from' says the answer is hidden in the clue.
'TWO' is hidden in the letters of 'petworth'.
(Other definitions for two that I've seen before include "Number in pair" , "One plus one" , "limited company?" , "Old song 'Tea for . . .'" , "II" .)