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

• autocrat
• monarch
• potentate
• sovereign
• sovran

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

Charles Edwards’ Lord Celebrimbor is one of the many rulers unknowingly under Sauron’s thumb, though Vickers finds earnestness in Sauron’s intentions. —Lauren Coates, Variety, 9 June 2025

Hamada, however, stated that the DFLP has maintained its relationship with the new rulers of Damascus and expects to do so for the foreseeable future. —Tom O'Connor, MSNBC Newsweek, 5 June 2025

Anything with anyone is possible now that planetary ruler, Venus, is riding the Bull. —Lisa Stardust, Refinery29, 4 June 2025

Neither his pressure on the Ukrainian leader, who Trump lambasted in the Oval Office, nor his recent scolding of the Kremlin ruler appear to have pushed the two sides any closer to a peace deal. —Matthew Chance, CNN Money, 2 June 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