I must finish fish bones (5)

I believe the answer is:

carpi

'bones' is the definition.
(I've seen this before)

'i must finish fish' is the wordplay.
'must finish' says to put letters next to each other.
'fish' becomes 'carp' (carp is a kind of fish**).
'i' after 'carp' is 'CARPI'.

(Another definition for carpi that I've seen is " Wrist bones - Capri (anag)".)

I've seen this clue in The Times.

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