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

Syria’s new rulers have asked Russia to hand the Assads over. — CNN Money, 11 Aug. 2026

Syria's new rulers have asked Russia to hand the Assads over. — FOXNews.com, 11 Aug. 2026

In a later conversation in that same episode, the women’s roles are switched — Rhaenyra is no longer the impatient interrogator but an aggrieved ruler who has no idea how to govern; Alicent is the soothing confidant offering wisdom to welcome ears. — Roxana Hadadi, Vulture, 10 Aug. 2026

Both superstars have accumulated seven champions and share the honor of claiming the third-most rulers ever. — Hugh McIntyre, Forbes.com, 10 Aug. 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing ruler

• co-ruler

Rhymes for ruler

• cooler
• 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