(1):

(n.) An arrangement of a fleet in a wedge or V formation.

(2):

(v. t.) To place in echelon; to station divisions of troops in echelon.

(3):

(v. i.) To take position in echelon.

(4):

(n.) 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.