the force that makes it difficult for one object to slide along the surface of another or to move through a liquid or gas

When you rub your hands together the friction produces heat. 揉搓双手时，摩擦会产生热量。

disagreement or unfriendliness caused by people having different opinions

There's a lot of friction between my wife and my mother. 我妻子和我母亲之间有很多龃龉。

Politics is a source of considerable friction in our family. 政治问题在我们家是矛盾的一大根源。

Border clashes have led to increased friction between the two countries. 边境冲突引发了两国间更大的摩擦。