A feather in one's cap finishing off claret (4)
I believe the answer is:
plum
'claret' is the definition.
The answer and definition can be both things that one consumes for nourishment as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'a feather in one's cap finishing off' is the wordplay.
'a feather in one's cap' becomes 'plume' (I've seen this in another clue).
'finishing off' means to remove the last letter.
'plume' with its last letter taken off is 'PLUM'.
Can you help me to learn more?
(Other definitions for plum that I've seen before include "Oval fruit with single hard stone" , "Dark reddish-purple colour: especially valued" , "Purple fruit" , "First-class - fruit" , "Shade" .)