gallon

noun

gal·​lon ˈga-lən 

: a unit of liquid capacity equal to 231 cubic inches or four quarts see Weights and Measures Table

Examples of gallon in a Sentence

Recent Examples on the Web

In 2009, a NASA probe deliberately crashed into the moon and struck water—at least 25 gallons of it—in the southern polar region. — Antonio Pequeño Iv, Forbes.com, 19 Aug. 2026

The floods also altered the course of the White River, which is now flowing into the Martin Marietta quarry at 96th Street and Gray Road, which can hold millions of gallons of water. — John Tufts, IndyStar, 19 Aug. 2026

Kiley pointed to Pan’s time in the Legislature to make his case, singling out his 2017 vote for a transportation package that raised the state gas tax by 12 cents per gallon. — Naomi Taxay, Sacbee.com, 18 Aug. 2026

PennEnvironment says the Philadelphia Water Department dumps over 12 billion gallons of untreated sewage and stormwater a year into the Delaware and Schuylkill rivers and their tributaries. — Joe Brandt, CBS News, 17 Aug. 2026

Word History

Etymology

Middle English galun, galoun, galon, a liquid measure, borrowed from Anglo-French galun, galon, jalon, from Old French jal-, base of jaloie "container for liquids, bucket" (going back to Vulgar Latin *gallēta, of uncertain origin) + -on, diminutive or particularizing suffix, going back to Latin -ō, -ōn-, suffix of persons with a prominent feature

Note: Presumed *gallēta (attested as Medieval Latin galeta "wine vessel, liquid measure" in 11th-century texts) has been linked to several classical Greek words for containers, as kálathos "kind of basket, wine cooler," kēlástra "milk pail" (so glossed by Hesychius), though none of these fit formally; on the other hand, kēlḗtēs, kalḗtēs "sufferer from a hernia" (from kḗlē, kálē "tumor, hernia"; see -cele) fits formally but requires a contextual and semantic leap ("one swollen or ruptured" > "container"?).

First Known Use

13th century, in the meaning defined above

Phrases Containing gallon

• ten-gallon hat

Rhymes for gallon

• alan
• ballon
• talon
• concanavalin
• enkephalin
• trifluralin

Kids Definition

gallon

noun

gal·​lon ˈgal-ən 

: a unit of liquid capacity equal to 231 cubic inches or four quarts see measure

Medical Definition

gallon

noun

gal·​lon ˈgal-ən 

1

: a United States unit of liquid capacity equal to four quarts or 231 cubic inches or 3.785 liters

2

: a British unit of liquid and dry capacity equal to four quarts or 277.42 cubic inches or 4.544 liters

called also imperial gallon