Criticise the effect of a loose bearing (5)

I believe the answer is:

knock

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'criticise' is the definition.
(I know that criticise can be written as knock)

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

Can you help me to learn more?

(Other definitions for knock that I've seen before include "Bump" , "Strike; setback" , "Disparage - seek admittance" , "Criticise; rap" , "Rap on door?" .)

I've seen this clue in The Globe and Mail.

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