- To billow is to swell outward or to move or rise up as if caused by waves.
- An example of billow is when fabric blows outward in the wind.
- An example of billow is when smoke wafts upward in gentle waves.
Smoke is billowing out of these factory chimneys.
billow definition by Webster's New World
- a large wave; great swell of water
- any large swelling mass or surge, as of smoke, sound, etc.
Origin: Old Norse bylgja: see belly
billow definition by American Heritage Dictionary
- A large wave or swell of water.
- A great swell, surge, or undulating mass, as of smoke or sound.
- To surge or roll in billows.
- To swell out or bulge: sheets billowing in the breeze.
Origin: From Old Norse bylgja, a wave; see bhelgh- in Indo-European roots.
- bilˈlow·i·ness noun
- bilˈlow·y adjective