Other forms: foxholes
A foxhole is a hole in the earth that's used by a soldier as a small fort. From the safety of a foxhole, troops are protected somewhat against enemy fire.
While trenches and quick fortifications or dugouts have been used throughout military history, the term foxhole didn't emerge until the very end of World War I, around 1918. The first recorded use was in a US army report from that year, describing German soldiers building "a hole in the ground sufficient to give shelter...to one or two soldiers." The Old English origin is fox-hol, "a fox's den."