Nationalist with peculiarity abruptly retracted sentence (4,4)

I believe the answer is:

send down

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

I don't understand how the rest of the clue works.

(Other definitions for send down that I've seen before include "Sentence to a prison term" , "Dismiss student" , "bang up" , "Assign time to" , "Expel (from university)" .)

I've seen this clue in The Independent.

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