Echelon

A military term applied to a certain arrangement of troops when several divisions are drawn up in parallel lines, each to the right or the left of the one preceding it, like “steps,” or the rounds of a ladder, so that no two are on the same alignment. Each division by marching directly forward can form a line with that which is in advance of it. There are two sorts of echelon, direct and oblique , the former of which is used in an attack or retreat.