To bellow means to shout in a deep, powerful voice, like a bull making its loud, rumbling call. When an angry coach bellows instructions across the field, everyone stops and listens because the sound is impossible to ignore. A ship captain might bellow commands during a storm so the crew can hear over the crashing waves.

The word suggests volume and force: bellowing means releasing sound with real power behind it, using your full voice to project across distance or cut through noise. Picture a frustrated parent bellowing “DINNER'S READY!” after calling politely three times with no response. A theater director might bellow “QUIET BACKSTAGE!” to get everyone's attention at once.

Animals bellow too. Bulls, elephants, and alligators all make deep, resonant calls that carry across long distances. When writers describe someone bellowing with laughter, they mean the person is laughing so hard and loud it fills the whole room.

Unlike screaming, which sounds high and sharp, bellowing is low and booming. It's the sound of authority, anger, or sometimes joy, expressed at maximum volume.

As a noun, a bellow is a loud, deep roar or shout.