Decide to call a halt to (8)

I believe the answer is:

conclude

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

I can't explain the rest of the clue.

(Other definitions for conclude that I've seen before include "Wind up" , "Reach an opinion based on reasoning" , "Finally decide" , "Terminate; deduce" , "Decide by reasoning or come to a close" .)

I've seen this clue in the Evening Standard.

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