Echelon

Ech"e*lon (?), v. t. (Mil.) To place in echelon; to station divisions of troops in echelon.

Ech"e*lon, v. i. To take position in echelon.

Change direction to the left, echelon by battalion from the right.
Upton (Tactics).

Ech"e*lon (ĕsh"e*lŏn), n. [F., fr. échelle ladder, fr. L. scala.] 1. (Mil.) An arrangement of a body of troops when its divisions are drawn up in parallel lines each to the right or the left of the one in advance of it, like the steps of a ladder in position for climbing. Also used adjectively; as, echelon distance. Upton (Tactics).

2. (Naval) An arrangement of a fleet in a wedge or V formation. Encyc. Dict.

Echelon lens (Optics), a large lens constructed in several parts or layers, extending in a succession of annular rings beyond the central lens; -- used in lighthouses.