friction

1. N-UNCOUNT If there is friction between people, there is disagreement and argument between them. (人与人之间的) 摩擦[also N in pl]

Sara sensed that there had been friction between her children. 萨拉感觉到她的孩子们中间出现了摩擦。

2. N-UNCOUNT Friction is the force that makes it difficult for things to move freely when they are touching each other. 摩擦力

The pistons are graphite-coated to reduce friction. 活塞表面涂有石墨以减少摩擦。