trench knife

American  

noun

1. a short knife for stabbing, sometimes equipped with brass knuckles as a guard, used in modern warfare in hand-to-hand combat.

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trench knife British  

noun

1. a double-edged steel knife, often with a guard in the form of a knuckle-duster, designed for close combat

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Etymology

Origin of trench knife

First recorded in 1915–20