Wear down painter finally settled in Lincoln (6)
I believe the answer is:
abrade
'wear down' is the definition.
(I've seen this before)
'painter finally settled in lincoln' is the wordplay.
'painter' becomes 'RA' (member of the Royal Academy of Arts).
'finally' suggests the final letters.
'in' is an insertion indicator.
'lincoln' becomes 'abe'.
The last letter of 'settled' is 'd'.
'ra'+'d'='rad'
'rad' placed into 'abe' is 'ABRADE'.
(Other definitions for abrade that I've seen before include "Shave" , "Wear away by erosion" , "Wear away by rubbing (6)" , "Scrape away, erode" , "Chafe" .)