Feeling resentful, drink (6)

I believe the answer is:

bitter

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'drink' is the definition.
(bitter is a kind of drink)

I don't understand how the rest of the clue works.

(Other definitions for bitter that I've seen before include "Resentful or angry through disappointment" , "Having a sharp, acid taste" , "Resentful, being piercingly cold" , "Sour like some English beer" , "English beer, sounds sour" .)

I've seen this clue in The Telegraph.

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