From Rhondda, left the valley (4)
I believe the answer is:
dale
'valley' is the definition.
(I know that Dale is a type of valley)
'from rhondda left the' is the wordplay.
'from' indicates a hidden word.
'DALE' is hidden in the letters of 'rhondda left the'.
(Other definitions for dale that I've seen before include "Valley; Trollope's Bell and Lily" , "Valley, particularly in Northern England" , "Valley, as in Yorkshire" , "See 8" , "Up hill and down . . . ." .)