the force that drives something forward 推进;推动力 wind/steam/jet propulsion 风力/蒸汽/喷气推进 The fish uses its tail fins for propulsion through the water. 这种鱼用尾鳍在水中推进。
Oxford Collocations DictionaryPropulsion is used before these nouns:- system
Word Originearly 17th cent. (in the sense ‘expulsion’): from medieval Latin propulsio(n-), from Latin propellere ‘drive before (oneself)’.