An excavation used to position guns so that they are protected from enemy fire.
1928, Edmund Blunden, Undertones of War, Penguin, published 2010, page 152:
On one of the preliminary evenings the new Colonel, with his habitual bad luck, sent forward from C Camp an officer […] to patrol the land over which our assault was intended, with a special eye to the enemy's concern with some ancient gunpits there.
