noun · in an upright or longitudinal direction; perpendicular to the horizon

请在这张纸上画一条竖线。

noun · a downward vertical stroke in Chinese characters (one of the basic strokes)

“十”字是由一横一竖组成的。

verb · to put something in an upright position; to stand up or raise

他竖起大拇指表示赞赏。