mainline carrier干线航空公司
Mainline West西部干线
mainline connector主线连接器
mainline block主索滑车
symbol mainline符号主线
mainline module主线模块
mainline railway干线铁路
mainline characteristic主线特征
ADJ（形容词） You can use mainline to describe people, ideas, and activities that belong to the most central, conventional, and normal part of a tradition, institution, or business. 主流的 [ADJ n]
We observe a striking shift away from a labour theory among all mainline economists.
我们发现在所有主流经济学家中出现了一种背离劳动理论的惊人变化。
V-T/V-I（及物动词/不及物动词） If people mainline a drug or if they mainline, they inject an illegal drug into themselves. 静脉注射 [非正式][usu cont]
We see him snorting and mainlining cocaine.
我们看到他吸食并注射可卡因。