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.

noun

beachcomber , breaker , crest , roller , surge , swell , tide , wave

verb

balloon , belly , bloat , bounce , bulge , ebb and flow , heave , pitch , puff up , ripple , rise and fall , rise up , rock , roll , swell , toss , undulate , wave , breaker , crest , float , sea , surge