A military engineer who does sapping (digging trenches or undermining fortifications) WordNet 3.0 & Open English WordNet

A sapper, also called a combat engineer, is a combatant or soldier who performs a variety of military engineering duties, such as breaching fortifications, demolitions, bridge-building, laying or clearing minefields, preparing field defenses, and road and airfield construction and repair. Wikipedia

A military function Wikipedia Disambiguation

Individual combat engineer soldier usually in British, Commonwealth, or U.S. military service. Wikipedia Disambiguation

Soldier who performs a variety of military engineering duties Wikidata

One who saps; specifically, one who is employed in working at saps, building and repairing fortifications, and the like. Often known as a combat engineer or military engineer. Wiktionary

One who saps; combat engineer. Wiktionary (translation)