Wide divide (4)
I believe the answer is:
gulf
'wide divide' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gulf that I've seen before include "Large deep bay" , "Rift" , "Deep inlet of the sea almost surrounded by land" , "Larger or more indented bay" , "Deep inlet of sea; chasm" .)