ruler

noun

rul·​er ˈrü-lər 

1

: one that rules

specifically : sovereign

2

: a worker or a machine that rules paper

3

: a smooth-edged strip (as of wood or metal) that is usually marked off in units (such as inches) and is used as a straightedge or for measuring

rulership

ˈrü-lər-ˌship 

noun

Synonyms of ruler

• monarch
• emperor
• sovereign
• king

Examples of ruler in a Sentence

a summit attended by a number of rulers from around the world

This ruler shows inches and centimeters.

Recent Examples on the Web

Archaeologists recently retrieved early medieval weapons from a lake in Poland — relics believed to be connected to the country's first rulers. —Andrea Margolis, FOXNews.com, 17 Dec. 2025

What does all of this tell us about the legendary ruler of New Vegas? —Lauren Huff, Entertainment Weekly, 17 Dec. 2025

Washington and its allies should systematically call out these divisions, as well as the deep resentments felt within regimes over malfeasance and corruption, aiming to drive wedges between the elites and the ruler. —Stephen Kotkin, Foreign Affairs, 16 Dec. 2025

The History of Hanukkah More than 2,000 years ago, Antiochus, a cruel ruler of the Greek Kingdom, imposed pagan beliefs on the Jewish people. —Holly Rizzuto Palker, Parents, 14 Dec. 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing ruler

• co-ruler

Rhymes for ruler

• cooler
• jeweller
• schooler
• schuller
• preschooler
• vestibular

Kids Definition

ruler

noun

rul·​er ˈrü-lər 

1

: sovereign entry 1 sense 1

2

: a straight strip of material (as wood or metal) marked off in units and used as a guide in drawing lines or for measuring