sapper

noun

1. a soldier employed in the construction of fortifications, trenches, or tunnels that approach or undermine enemy positions.

noun

1. a soldier who digs trenches
2. (in the British Army) a private of the Royal Engineers

noun

1. real name Herman Cyril McNeile . 1888–1937, British novelist, author of the popular thriller Bull-dog Drummond (1920) and its sequels

n.1620s, in a military context, “soldier employed in building fortifications,” agent noun from sap (v.1).