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

billowy

2 of 2

adjective

bil·​lowy ˈbi-lə-wē 

sometimes -er/-est

1

: characterized by billows

the billowy sea

2

: suggestive of billows

the billowy prairie

Synonyms of billow

Noun

• wave
• swell

Examples of billow in a Sentence

Noun

Billows of smoke poured out of the burning building.

the rolling billows of the sea

Recent Examples on the Web

Noun

Smoke billows from southern Lebanon following Israeli strikes as seen from Nabatieh, Lebanon, on Sunday. —Freddie Clayton, NBC news, 31 May 2026

Smoke billows following an Israeli strike on the area of the Rawdat al-Salihin Mosque and the nearby cemetery in the southern city of Nabatieh, Lebanon, May 26, 2026. —CBS News, 27 May 2026

Video footage of the crash's aftermath obtained by NBC shows the vehicle significantly engulfed in orange flames emitting billows of black smoke. —Rachel Raposas, PEOPLE, 13 May 2026

Father and son, both members of the Eastern Shoshone Tribe, stare out at a sea of green grass and buffalo berry bushes as a herd of 30 or so bison munch patches of grass, flick their tails at flies, and flop onto the ground, creating brief billows of dust. —Christine Peterson, Outdoor Life, 5 Mar. 2026

Word History

Etymology

Noun

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

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