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.
Astrology. 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.
Also called: rule a strip of wood, metal, or other material, having straight edges graduated usually in millimetres or inches, used for measuring and drawing straight lines