Entrench

Entrench (verb) to dig trenches for defensive purposes around (oneself, a military position, etc.).

Source: TTTC page 174. The others stood in a circle, watching the water, then after a time somebody said, "We can't just leave him there," and the men nodded and got out their entrenching tools and began digging.

Context Clue: Logic and parts of word. Trench would be a defensive line in war and to "en"trench would be like to create a trench. Also, the men began digging with their entrenching tools and it was to get kiowa out so it would be logical that to entrench is to create a trench.

Original sentence: In World War I, most of the soldier's time was spent entrenching their positions to fortify their position and waiting for an enemy attack.