Sort out instruction to waiter (5)

I believe the answer is:

order

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

I can't explain the rest of the clue.

(Other definitions for order that I've seen before include "Rank" , "plan to reorganise Europe with 1a [NEW]" , "System" , "Fettle - kilter" , "Tidy state - that's a command" .)

I've seen this clue in The Sun.

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