ruler
Americannoun
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a person who rules or governs; sovereign.
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Also 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.
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a person or thing that rules paper, wood, etc.
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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.
noun
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a person who rules or commands
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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
Other Word Forms
- subruler noun
- underruler noun
Etymology
Origin of ruler
Explanation
The leader of a country is a ruler. If you're a queen, a sultan, or a czar, you're a ruler. Besides "person who rules or governs," you can define ruler as a measuring device that's marked with inches or centimeters. You can measure the diameter of a circle with a ruler, and you can also draw a perfectly straight line using its edge. Both meanings stem from the verb rule, "to exercise power" or "to control," which came to also mean "mark with lines" in the 1590s.
Vocabulary lists containing ruler
Measurement and Data, List 2
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"Culture Clash"
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Measurement and Data
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Rebecca Ebbage, 32, says the day she started showing TSW symptoms was the day her skin became her "ruler".
From BBC • Mar. 28, 2026
The spat is emerging as a source of frustration in Congo, which already holds a historic grudge with its old colonial ruler.
From The Wall Street Journal • Mar. 28, 2026
"Only those nations ruled by kings or dictators display the image of their sitting ruler on the coins of the realm," he said.
From Barron's • Mar. 20, 2026
In a couple of quick paragraphs, he said Iraq's ruler Saddam Hussein should comply with the United Nations resolutions to pull out of Kuwait.
From BBC • Mar. 11, 2026
It was only a few feet tall, maybe coming up to my chin, but its arms sprawled out straight as a ruler in all directions.
From "Tristan Strong Punches a Hole in the Sky" by Kwame Mbalia
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
