To utter a loud, deep, prolonged sound, especially in distress, rage, or excitement. To laugh loudly or excitedly. To make or produce a loud noise or din: The engines roared. To be disorderly or rowdy. To breathe with a rasping sound. Used of a horse. To utter or express with a loud, deep, and prolonged sound. See Synonyms at shout. To put, bring, or force into a specified state by roaring: The crowd roared itself hoarse. A loud deep prolonged sound or cry, as of a person in distress or rage. The loud deep cry of a wild animal. A loud prolonged noise, such as that produced by waves. A loud burst of laughter. roar back To have great success after a period of lackluster performance; make a dramatic recovery: lost the first set but roared back to win the match.