n. 主线, 干线
vt.vi. (美)(非正式)把(毒品)直接注射入静脉
在线英汉词典

mainline的短语、例句：

mainline v [Ipr, Tn, Tn.pr] ~ sth (into sth) (sl 俚) inject (a drug) into a large vein for stimulation, often because of addiction 将（毒品）注入大静脉（常因犯瘾）:be mainlining on hard drugs 注射硬性毒品
She mainlinedheroin (into a vein in her arm). 她（向臂静脉中）注射海洛因.