/rooh"leuhr/ , n.
1. a person who rules or governs; sovereign.
2. Also, rule . a strip of wood, metal, or other material having a straight edge and usually marked off in inches or centimeters, used for drawing lines, measuring, etc.
3. a person or thing that rules paper, wood, etc.
4. Astrol. the planet primarily associated with any sign of the zodiac or any house of the horoscope: The ruler of Aries is Mars. The ruler of Taurus is Venus.
[ 1325-75; ME; see RULE, -ER 1 ]