Catch report of GIs in Britain during the war, as the saying goes (8)

I believe the answer is:

overhear

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'catch' is the definition.
('overhear' can be a synonym of 'catch')

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for overhear that I've seen before include "Accidentally discover" , "Earwig" , "Pick up" , "broadcasts in this area" , "Catch unintentionally" .)

I've seen this clue in the Irish Times.

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