Weymouth’s county (6)
I believe the answer is:
dorset
'weymouth's county' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dorset that I've seen before include "area of Portland Bill" , "South-west area" , "Sorted out the southern English county" , "Strode (anag.)" , "Weymouth's county" .)