noun
ruler
ROO-luh
noun
1
A flat, straight-edged tool marked with measurement units, used for drawing lines or measuring length.
"He measured the box with a wooden ruler."
2
A person who governs or holds supreme authority over a country or people.
"The ancient ruler expanded the empire's borders significantly."
How to Use Ruler
Learner’s notesIn plain EnglishEither the measuring tool in your pencil case, or a monarch/leader in charge of a country.
Common pairings
ruler and pencil
absolute ruler
sole ruler
Word Forms
rulered past tense, rulers plural, rulers singular
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He measured the box with a wooden _____.
Etymology
From Middle English reuler, formed from rule plus the agent suffix -er.