The term REVVED ENGINE SOUND can be summarized by two crossword solutions: VROOM (5 letters) and ROAR (4 letters). VROOM is a sound made by an engine when it is revved up, usually associated with a car or motorcycle. ROAR is a loud, deep sound made by an engine when it is revved up, often associated with a larger vehicle such as a truck or a boat. Both sounds are indicative of a powerful engine and are often heard in racing or other motor sports.