- 减速器 jiǎnsùqì reduction geara mechanical device used to reduce the speed of a machine; also called [[减速箱|減速箱|jian3 su4 xiang1]]
- 减速剂 jiǎnsùjì moderatorA substance used in a nuclear reactor to slow down the speed of neutrons without absorbing them to maintain a chain reaction.
- 减速条 jiǎnsùtiáo speed bumpridge or bar installed across a road surface to force drivers to reduce their speed
- 减速火箭 jiǎnsùhuǒjiàn retrorocketa rocket engine that provides thrust in the opposite direction to the motion of a spacecraft, used to slow it down
- 减速箱 jiǎnsùxiāng gearboxa mechanical housing or case containing reduction gears used to decrease the output speed of a motor or engine
- 减速垫 jiǎnsùdiàn speed bumpa raised strip on a roadway surface designed to slow down motor-vehicle traffic
- 减速带 jiǎnsùdài speed bumpA strip or ridge installed across a roadway to force drivers to slow down; also called [[减速条|減速條|jian3 su4 tiao2]] or [[减速垫|減速墊|jian3 su4 dian4]]