Item one put in claret when drunk (7)
I believe the answer is:
article
'item' is the definition.
(I've seen this in another clue)
'one put in claret when drunk' is the wordplay.
'one' becomes 'i' (Roman numeral).
'put in' means one lot of letters goes inside another.
'when drunk' is an anagram indicator (a drunken or disorderly form of the letters).
'claret' anagrammed gives 'artcle'.
'i' placed into 'artcle' is 'ARTICLE'.
(Other definitions for article that I've seen before include "leader" , "Division" , "News story" , "Newspaper item" , "Newspaper piece" .)