切线

切线	qiē xiàn	tangent line (geometry)
切	qiē	to cut; to slice; to carve / (math) tangential
切	qiè	definitely; absolutely (not) / (scoffing or dismissive interjection) Yeah, right.; Tut! / to grind / (bound form) close to / (bound form) eager / to correspond to / (used to indicate that the fanqie 反切 system should be applied to the previous two characters)
线	xiàn	variant of 线
线	xiàn	thread / string / wire / line / CL:条,股,根 / (after a number) tier (unofficial ranking of a Chinese city)