1
- a level or rank in an organization, a profession, or society（组织、职业或社会的）等级; 阶层：
the upper echelons of the business world.
工商界的上流阶层。
1.1
- often with modifier a part of a military force differentiated by position in battle or by function（处于战场某方位或执行某任务的）部队：
the rear echelon.
后卫部队。
2
- Military a formation of troops, ships, aircraft, or vehicles in parallel rows with the end of each row projecting further than the one in front【军】（部队、船只、飞机或车辆排列成的） 梯队, 梯次配置。
with obj.
- Military arrange in an echelon formation【军】使列成梯队, 使形成梯次配置：
as noun echeloning the echeloning of fire teams.消防队的梯次配置。
词源
late 18th cent. (in sense 2)： from French échelon, from échelle 'ladder', from Latin scala.