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

The Moon trines your ruler Saturn, supporting honest discussions about household costs, family needs, or who is responsible for what. — Tarot.com, Baltimore Sun, 8 Sep. 2026

The United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), is presently being investigated for ties to the terrorist rulers of Gaza. — Beth Bailey, FOXNews.com, 7 Sep. 2026

Trump posted a second image of himself as a powerful technological ruler. — Paloma Chavez, PEOPLE, 7 Sep. 2026

But when English ruler Edward the Confessor dies, Harold is crowned king, leading William to assemble a fleet and set sail for England. — ABC News, 7 Sep. 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