\Ech"e*lon\ ([e^]sh"e*l[o^]n), n. [F., fr. ['e]chelle
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.

\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).