Exploits fish drink (9)

I believe the answer is:

milkshake

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

'exploits fish' is the wordplay.
'exploits' becomes 'milks' (milking is a kind of exploiting).
'fish' becomes 'hake' (hake is a kind of fish**).
'milks'+'hake'='MILKSHAKE'

(Another definition for milkshake that I've seen is " Cold whisked drink".)

I've seen this clue in The Independent.

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