Beam accepts endless argument for sanction (6)

I believe the answer is:

ratify

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'for sanction' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for ratify that I've seen before include "Approve officially" , "Approve and formally accept" , "Authorise" , "Confirm or accept, say a treaty" , "Fit ray (anag.)" .)

I've seen this clue in The Telegraph.

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