垂线 Traditional form: 垂線 Pinyin (reading): chuíxiàn Definitions: (math.) perpendicular line vertical line Characters: 垂 - to hang, to dangle; to hand down, to bequeath; almost, near 线 - line, thread, wire; clue, trail Traditional characters: 垂 - to hang, to dangle; to hand down, to bequeath; almost, near 線 - line, thread, wire; clue, trail