society > armed hostility > warrior > soldier > soldier with special duty > [noun] > pioneer (3)
Military. A member of an infantry group going with or ahead of an army or regiment to dig trenches, repair roads, and clear terrain in readiness for…
A soldier or other person employed in digging trenches, pits, etc.; = pioneer, n. 1. Obsolete.
A person who works or is armed with an axe or hatchet; spec. such a person acting as a pioneer for a military unit. Obsolete.