主线

主线	zhǔ xiàn	main line (of communication) / main thread (of a plotline or concept) / central theme
主	zhǔ	owner / master / host / individual or party concerned / God / Lord / main / to indicate or signify / trump card (in card games)
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)