- (
geology 地质学 a place where there is a long break in the rock that forms the surface of the earth and where earthquakes are more likely to happen The fact that Tokyo sits directly on a fault line has resulted in a string of powerful earthquakes over the centuries. 东京直接位于断层线上，这一事实导致了几个世纪以来的一系列强烈地震。
an issue that people disagree about and may, as a result, lead to conflict The two men are from opposite sides of the nation's political fault line. 这两个人来自国家政治断层线的相反两侧。