bel·low / ˈbelō/ • v. [intr.] (of a person or animal) emit a deep loud roar, typically in pain or anger: he bellowed in agony [as n.] (bellowing) the bellowing of a bull. ∎  shout something with a deep loud roar: [tr.] the watchers were bellowing encouragement “God send the right!” he bellowed. ∎  [tr.] sing (a song) loudly and tunelessly: he got thrown out of bars for bellowing Portuguese folk songs• n. a deep roaring shout or sound: a bellow of rage.

bellow roar as a bull. XIV. ME. belwen, of uncert. orig.