roar

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

• noun The loud deep cry of a wild animal, especially a lion or other wild cat.
• noun A loud, deep, prolonged sound or cry, as of a person in distress or rage.
• noun A loud prolonged noise, such as that produced by waves.
• noun A loud burst of laughter.
• intransitive verb To produce or utter a roar.
• intransitive verb To laugh loudly or excitedly.
• intransitive verb To make or produce a loud noise or din.
• intransitive verb To move while making a loud noise.
• intransitive verb To breathe with a rasping sound. Used of a horse.
• intransitive verb To utter or express loudly. synonym: yell.
• intransitive verb To put, bring, or force into a specified state by roaring.

from The Century Dictionary.

• To cry with a full, loud, continued sound; bellow, as a beast.
• To cry aloud, as in distress or anger.
• To make a loud, continued, confused sound, as winds, waves, a multitude of people shouting together, etc.; give out a full, deep sound; resound.
• To laugh out loudly and continuously; guffaw.
• To behave in a riotous and bullying manner.
• To make a loud noise in breathing, as horses in a specific disease. See roaring, n., 2.
• Synonyms and To bawl, howl, yell.
• To boom, resound, thunder, peal.
• To cry aloud; proclaim with loud noise; utter in a roar; shout: as, to roar out one's name.
• noun A full, loud, and deep cry, as of the larger beasts.
• noun A loud, continued, confused sound; a clamor; tumult; uproar.
• noun The loud, impassioned cry of a person in distress, pain, anger, or the like; also, a boisterous outcry of joy or mirth: as, a roar of laughter.

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

• intransitive verb To cry with a full, loud, continued sound.
• intransitive verb To bellow, or utter a deep, loud cry, as a lion or other beast.
• intransitive verb To cry loudly, as in pain, distress, or anger.
• intransitive verb To make a loud, confused sound, as winds, waves, passing vehicles, a crowd of persons when shouting together, or the like.
• intransitive verb To be boisterous; to be disorderly.
• intransitive verb To laugh out loudly and continuously.
• intransitive verb To make a loud noise in breathing, as horses having a certain disease. See Roaring, 2.
• intransitive verb a roaring, noisy fellow; -- name given, at the latter end Queen Elizabeth's reign, to the riotous fellows who raised disturbances in the street.
• intransitive verb (Naut.) a sailor's name for the stormy tract of ocean between 40° and 50° north latitude.
• noun The deep, loud cry of a wild beast.
• noun The cry of one in pain, distress, anger, or the like.
• noun A loud, continuous, and confused sound.
• noun A boisterous outcry or shouting, as in mirth.
• transitive verb To cry aloud; to proclaim loudly.

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

• verb To make a loud, deep cry, especially from pain, anger, or other strong emotion.
• verb To laugh in a particularly loud manner.
• verb Of animals (especially the lion), to make a loud deep noise.
• verb Generally, of inanimate objects etc., to make a loud resounding noise.
• noun A long, loud, deep shout made with the mouth wide open.
• noun The cry of the lion.
• noun The deep cry of the bull.
• noun A loud sound as of a motorbike or a similar engine.
• noun A show of strength or character.

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

• verb make a loud noise, as of animal
• verb laugh unrestrainedly and heartily
• verb make a loud noise, as of wind, water, or vehicles