echelon

英 ['eʃəlɒn; 'eɪʃ-] 美['ɛʃəlɑn]

• n. 梯形；梯次编队；梯阵；阶层
• vi. 形成梯队
• vt. 排成梯队

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