billow

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A large wave or swell of water.
• noun A great swell, surge, or undulating mass, as of smoke or sound.
• intransitive verb To surge or roll in billows.
• intransitive verb To swell out or bulge.
• intransitive verb To cause to billow.

from The Century Dictionary.

• To swell; rise and roll in large waves or surges.
• To raise in waves or billows.
• noun A great wave or surge of the sea, occasioned usually by a violent wind: much used in figurative applications, and often, especially in the plural, as merely equivalent to wave: as, the billows of sorrow rolled over him.
• noun Synonyms See wave.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb To surge; to rise and roll in waves or surges; to undulate.
• noun A great wave or surge of the sea or other water, caused usually by violent wind.
• noun A great wave or flood of anything.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A large wave, swell, surge, or undulating mass of something, such as water, smoke, fabric or sound
• verb To surge or roll in billows
• verb To swell out or bulge

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a large sea wave
• verb become inflated
• verb move with great difficulty
• verb rise and move, as in waves or billows
• verb rise up as if in waves