Noun:

1. one who intrudes or pushes himself forward

2. a small rocket engine that provides the thrust needed to maneuver a spacecraft

pushern.推进者；推动器；(毒品等的)非法销售者；推杆

1. The thruster contained a large-diameter, slowly rotating blade with nozzles that diffused the propulsive flow, minimizing the churning that would otherwise disturb the caked silt.
   机器的推进器包含了大直径慢速转动的螺旋桨，而且推进水流由喷嘴送出，以避面剧烈搅动扰乱了结块的淤泥。