This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Plural form of echelon.

"The second echelons, that is, the remainder, of these divisions were to follow as soon as they could be unloaded; directly following them, if possible with tank elements in the first wave, would come the second wave of six panzer and three motorized divisions, [And two motorized regiments.] split up equally between each Army's sector and leaving from the same areas as those of the first wave."

echeloned    echeloning    echelons   

diffraction grating    grating    military group    force    military unit   

echelon spectroscope    echelon diffraction grating   

brigade    platoon    headquarters    aviation    reconnaissance