echelon
英 ['e??l?n; 'e??-]
美['???lɑn]
- n. 梯形；梯次編隊(duì)；梯陣；階層
- vi. 形成梯隊(duì)
- vt. 排成梯隊(duì)
英英釋意
- 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