intransitive verb

1. to utter a loud, deep, rumbling sound, as a lion or a person in excitement, pain, anger, etc.
2. to breathe with a loud, hoarse, rasping noise, as a diseased horse
3. to talk or laugh loudly and boisterously
4. to make a loud noise in moving, operating, etc., as a motor or gun
5. to resound with a noisy din

Etymology: ME raren < OE rarian, akin to Ger rehren < IE echoic base *rei-, to cry out > Sans rǡyati, (he) bellows, ON rāmr, hoarse

transitive verb

1. to utter in or express with a loud, deep sound
2. to make, put, force, etc. by roaring to roar oneself hoarse

noun

1. a loud, deep, rumbling sound, as of a lion, bull, person or crowd shouting, etc.; sound of roaring
2. a loud burst of laughter
3. a loud noise, as of waves, a storm, a motor, etc.; din