Noun

• S: (n) boom, roar, roaring, thunder (a deep prolonged loud noise)
• S: (n) bellow, bellowing, holla, holler, hollering, hollo, holloa, roar, roaring, yowl (a very loud utterance (like the sound of an animal)) "his bellow filled the hallway"
• S: (n) roar (the sound made by a lion)

Verb

• S: (v) roar, howl (make a loud noise, as of wind, water, or vehicles) "The wind was howling in the trees"; "The water roared down the chute"
• S: (v) thunder, roar (utter words loudly and forcefully) "`Get out of here,' he roared"
• S: (v) howl, ululate, wail, roar, yawl, yaup (emit long loud cries) "wail in self-pity"; "howl with sorrow"
• S: (v) roar (act or proceed in a riotous, turbulent, or disorderly way) "desperadoes from the hills regularly roared in to take over the town"-R.A.Billington
• S: (v) bellow, roar (make a loud noise, as of animal) "The bull bellowed"
• S: (v) roar, howl (laugh unrestrainedly and heartily)