Give up having succeeded to discharge power (5)

I believe the answer is:

reign

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'power' is the definition.
(reign can mean time in power)

I cannot understand how the remainder of the clue works.

(Other definitions for reign that I've seen before include "Rule of monarch" , "time in power" , "Spell in office" , "Rule over in Niger" , "Sovereignty" .)

I've seen this clue in The Times and The Sunday Times.

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