Brisling processed in parts (5)

I believe the answer is:

sprat

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'brisling' is the definition.
(synonyms)

'processed in parts' is the wordplay.
'parts' anagrams to 'SPRAT'.
Though, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for sprat that I've seen before include "chap giving richer course material to the Dutch" , "'Set a . . . . . to catch a whale'" , "Small sea fish" , "Herring's smaller relative" , "Parts (anag.)" .)

I've seen this clue in the Evening Standard.

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