From Longman Dictionary of Contemporary Englishbelt something ↔ out phrasal verbAPMto sing a song or play an instrument loudly She was belting out old Broadway favourites. → belt→ See Verb table
Examples from the Corpus
belt out• Mark was carrying his jacket, and Clare regretted that she had not taken off her stockings and belt before coming out.• Almost all of the moving objects seen are slow-moving belt asteroids, out between the orbits of Mars and Jupiter.• When the conveyor belt stops, out come the text books.• She turns back toward him, to unlatch the seat belt and run out of the car.• The machinery gave more than the usual trouble; shafting and belting wore out prematurely.• As he fumbled with his belt he shouted out to the others to throw their grenades. 