Cancels yearbooks after the fifth fails to show (6)

I believe the answer is:

annuls

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'cancels' is the definition.
(annulling is a kind of cancelling)

I don't understand the remainder of the clue.

(Other definitions for annuls that I've seen before include "Renders boid" , "Cancels, makes void" , "Repeals or rescinds" , "Declares invalid" , "Cancels officially" .)

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

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