An echelon in an organization or society is a level or rank in it.
例句
...the lower echelons of society.社會等級較低的階層
N-COUNT
（士兵、車輛、軍艦、飛機等的）梯形編隊,梯隊
An echelon is a military formation in which soldiers, vehicles, ships, or aircraft follow each other but are spaced out sideways so that they can see ahead.
英漢詞典釋義
n.
(機構(gòu)中的)等級,階層
Officers were drawn largely from the top echelons of society.這些官員大都來自社會上層。
英英詞典釋義
Noun
1. a body of troops arranged in a line
2. a diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset