Visit takes in worn-out county (8)
I believe the answer is:
cornwall
'county' is the definition.
'visit takes in worn-out' is the wordplay.
'visit' becomes 'call' (call is a kind of visit).
'takes in' means one lot of letters goes inside another.
'out' indicates an anagram (out can mean wrong or inaccurate).
'worn' is an anagram of 'ornw'.
'call' placed around 'ornw' is 'CORNWALL'.
(Other definitions for cornwall that I've seen before include "County touching only one other" , "Southwestern English county" , "Crown all in the English county, strangely" , "Land" , "Part of 1 25 [KING LEAR]" .)