quadrillion

noun

qua·​dril·​lion kwä-ˈdril-yən 

US : a number equal to 1 followed by 15 zeros see Table of Numbers

also, British : a number equal to 1 followed by 24 zeros see Table of Numbers

quadrillion adjective

quadrillionth

kwä-ˈdril-yən(t)th 

adjective or noun

Examples of quadrillion in a Sentence

Recent Examples on the Web

All that melted ice turned into nearly 3 quadrillion gallons of water, which pushed global sea levels up about an inch since 1979, on top of other climate factors raising ocean heights, the report said. — Seth Borenstein, Los Angeles Times, 16 Sep. 2026

Ever since the 1950s, when this curiosity was observed, scientists have been trying to figure out what might cause shell direction to change in quadrillions of microorganisms in unison. — Quanta Magazine, 11 Sep. 2026

The new atlas covers everything else and contains a whopping petabyte of data—a quadrillion bytes. — Peter Hall, Scientific American, 8 Sep. 2026

The Road To Quadrillionistan A quadrillion-dollar bitcoin market sounds silly today. — Dave Birnbaum, Forbes.com, 21 Aug. 2026

Word History

Etymology

French, from Middle French, from quadri- + -illion (as in million)

First Known Use

circa 1690, in the meaning defined above

Rhymes for quadrillion

• castilian
• civilian
• cotillion
• pavilion
• postilion
• reptilian
• vermilion
• vermillion
• billion
• million
• pillion
• trillion

Kids Definition

quadrillion

noun

qua·​dril·​lion kwä-ˈdril-yən 

US : a number equal to 1 followed by 15 zeros see number

also, British : a number equal to 1 followed by 24 zeros see number