State of article found in pit (5)
I believe the answer is:
maine
'state' is the definition.
(US state)
'article found in pit' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'found in' means one lot of letters goes inside another.
'pit' becomes 'mine' (mining pit).
'a' inserted inside 'mine' is 'MAINE'.
'of' acts as a link.
(Other definitions for maine that I've seen before include "NE US state" , "US state, capital Augusta (5)" , "state of USA" , "North-easterly US state" , "somewhere in America" .)