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

Before Foreign Tongues debuted, the Rolling Stones were tied with Taylor Swift, who remains steady with 14 rulers and now slips to fourth place among all acts. — Hugh McIntyre, Forbes.com, 21 July 2026

After defeating Troy and setting sail for home, Odysseus, the ruler of a small kingdom, and his men are blown off course. — Brent Lang, Variety, 21 July 2026

The third ruler of the 12th dynasty who reigned during Egypt’s Middle Kingdom, little is known about Amenemhat II other than his death around 1895 BCE. — Andrew Paul, Popular Science, 17 July 2026

Matt Damon stars as Odysseus, the ruler of Ithaca who leaves behind his wife, Penelope (Anne Hathaway, in another round with Nolan), and son, Telemachus (Tom Holland), to fight in the Trojan War. — Savannah Salazar, Vulture, 17 July 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