Out of this trench? That's excessive (4-3-3)

I believe the answer is:

over-the-top

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'excessive' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

(Other definitions for over-the-top that I've seen before include "Excessively extreme" , "To an exaggerated degree" , "Theatrically excessive" .)

I've seen this clue in The Daily Express.

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