mainline是什么意思 n. 主线, 干线vt.vi. (美)(非正式)把(毒品)直接注射入静脉 v. inject into the vein mainline的用法和例句: 1. Well, every once in awhile but I don't mainline it. 偶尔会吸一下 但是从来没有注射过 2. I thought I was mainlining the secret truth...