billow

1 of 2

noun

bil·​low ˈbi-(ˌ)lō 

1

: wave

especially : a great wave or surge of water

the rolling billows of the sea

2

: a rolling mass (as of flame or smoke) that resembles a high wave

Billows of smoke poured out of the building.

billows of fog

billowy

ˈbi-lə-wē 

adjective

billow

2 of 2

verb

billowed; billowing; billows

intransitive verb

1

: to rise or roll in waves or surges

the billowing sea

2

: to bulge or swell out (as through action of the wind)

billowing clouds

… the flags … billowed out in pride …

—G. B. Oxnam

transitive verb

: to cause to billow

a field of burning grass billowing thick black clouds of smoke into the sky

—Donald Windham

Synonyms

Noun

• surge
• swell
• wave

Verb

• bag
• balloon
• beetle
• belly
• bulge
• bunch
• jut
• overhang
• poke
• pooch [chiefly dialect]
• pouch
• pout
• project
• protrude
• stand out
• start
• stick out
• swell

Examples of billow in a Sentence

Noun

Billows of smoke poured out of the burning building.

the rolling billows of the sea

Verb

the curtains in the open windows billowed in the summer wind

Recent Examples on the Web

Noun

Steam billows from the donabe, and the scent filling the air brings to mind a Chinese banquet. —Ingu Chen, Vogue, 27 Jan. 2025

In a video posted to X and verified by NBC News, hundreds of people can be seen escaping from the prison as plumes of black smoke billow nearby and what sounds like gunshots ring out. —Astha Rajvanshi, NBC News, 6 Feb. 2025

Verb

As the suspect vehicle fled the area, smoke could be seen billowing up from the rear yard of the home, and within 30 seconds, a large explosion was observed, and the house became engulfed in flames. —Jon Haworth, ABC News, 18 Feb. 2025

The fire spread quickly, and dark smoke billowed from the building by the time rescuers arrived, Chief Hong told reporters. —John Yoon, New York Times, 14 Feb. 2025

Word History

Etymology

Noun and Verb

Old Norse bylgja; akin to Old High German balg bag — more at belly

First Known Use

Noun

1552, in the meaning defined at sense 1

Verb

1592, in the meaning defined at intransitive sense 1

Rhymes for billow

• pillow
• armadillo
• caudillo

Kids Definition

billow

1 of 2 noun

bil·​low ˈbil-ō 

1

: wave entry 2 sense 1

especially : a large wave

2

: a rolling mass like a high wave

billows of smoke

billow

2 of 2 verb

1

: to rise or roll in waves

the billowing ocean

2

: to bulge or swell out

sails billowing in the breeze