a level of command, authority, or rank: the top echelon of city officials.
2.
a formation of troops, ships, airplanes, etc., in which groups of soldiers or individual vehicles or craft are arranged in parallel lines, each to the right or left of the one in front, so that the whole presents the appearance of steps.
3.
one of the groups of a formation so arranged.
4.
Also called echelon grating.Spectroscopy. a diffraction grating that is used in the resolution of fine structure lines and consists of a series of plates of equal thickness stacked in staircase fashion.
–verb (used with object), verb (used without object)
5.
to form in an echelon.
Origin: 1790–1800; < F échelon, orig. rung of a ladder, OF eschelon, equiv. to esch(i)ele ladder (< L scāla;see scale3) + -on n. suffix
A formation of troops in which each unit is positioned successively to the left or right of the rear unit to form an oblique or steplike line.
A flight formation or arrangement of craft in this manner.
A similar formation of groups, units, or individuals.
A subdivision of a military or naval force: a command echelon.
A level of responsibility or authority in a hierarchy; a rank: a job in the company's lower echelon.
tr. & intr.v.
ech·e·loned, ech·e·lon·ing, ech·e·lons To arrange or take place in an echelon.
[French échelon, from Old French eschelon, rung of a ladder, from eschiele, ladder, from Late Latin scāla, back-formation from Latin scālae, steps, ladder; see skand- in Indo-European roots.]
[esh-uh-lon] 
