mainline mainlander • main line · · · Info · Definitions · Characters · · mainline · · Text Latin · · Script 8 · · Length 2 · · Syllables Definitions · · · (verb) inject into the vein. Example: "She is mainlining heroin." · · Verb Definition 1 Characters · · a latin small letter a U+0061 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E