n.[C]

1. 統治者；管理者；支配者
   She was then ruler of Egypt.

   她當時是埃及的統治者。

2. 劃線人；劃線機
3. 尺，直尺；劃線板
   The child used a ruler to draw straight lines.

   這孩子用一把直尺劃直線。

n.

1. a person or agent exercising government or control.
2. a straight-edged strip of rigid material, marked at regular intervals and used to draw straight lines or measure distances.