Destroy article covered in oil, better to be replaced (10)
I believe the answer is:
obliterate
'destroy' is the definition.
(thesaurus)
'article covered in oil better to be replaced' is the wordplay.
'article' becomes 'a' (indefinite article).
'covered in' means one lot of letters goes inside another.
'to be replaced' indicates anagramming the letters.
'oil'+'better'='oilbetter'
'oilbetter' with letters rearranged gives 'obliterte'.
'a' going into 'obliterte' is 'OBLITERATE'.
(Other definitions for obliterate that I've seen before include "Eliminate" , "use eraser" , "Destroy all traces" , "Eradicate" , "Put an end to" .)