bil•lowPronunciation: (bil'ō), [key]
a great wave or surge of the sea.
any surging mass: billows of smoke.
to rise or roll in or like billows; surge.
to swell out, puff up, etc., as by the action of wind: flags billowing in the breeze.
to make rise, surge, swell, or the like: A sudden wind billowed the tent alarmingly.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.