echelon

• Nom désignant un niveau ou un grade dans une organisation, une profession ou une société, ou encore une disposition de troupes ou d'avions en lignes parallèles.

A noun referring to a level or rank in an organization, profession, or society, or a formation of troops or aircraft arranged in parallel lines.

1. Military formationC1formal

   A body of troops, ships, or aircraft arranged in a line or in parallel lines with a regular offset.

   Échelon (formation militaire)

   • The bombers flew in an echelon formation.
   • The troops advanced in echelons to provide mutual support.
   • The naval fleet was arranged in a staggered echelon.

2. Optical deviceC2formalscientific

   A diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset, used to analyze light spectra.

   Réseau à échelons

   • The scientist used an echelon grating to study the spectral lines.
   • The echelon's stepwise arrangement allows for high-resolution diffraction.
   • This type of echelon is essential in advanced spectroscopy.