English Reference
noun · verb · interjection

boom

n. · v. · interj.
US /ˈbum/ UK /bˈuːm/ boom UK spelling boomed, booms

  1. 01 B1 Intermediate Economics

    n.a period of great success and fast growth in business or the economy.

    n.a period of rapid economic expansion, prosperity, or high market activity.

    Simple

    The city experienced a housing boom as thousands of new workers moved in for jobs.

    In context

    Economists debated whether the current tech boom was a sustainable growth period or a speculative bubble destined to burst.

  2. 02 B2 Upper Intermediate

    n.a deep, loud, and powerful sound like an explosion.

    n.a deep, resonant, and low-frequency sound, often associated with explosions or heavy impacts.

    Simple

    We heard a distant boom and realized the construction crew was blasting rock.

    In context

    The sonic boom shattered several windows in the village as the experimental jet exceeded the speed of sound.

    thunderreverberationroar
  3. 03 C1 Advanced Technical

    n.a long, movable pole used to hold a microphone or camera, or to support a sail on a boat.

    n.a long spar or movable arm used in various technical contexts, including maritime rigging and cinematic audio capture.

    Simple

    The sound assistant held the boom high to keep the microphone out of the shot.

    In context

    The sailor swung the boom across the deck as the wind shifted, narrowly avoiding the passengers standing near the stern.

  4. 04 B1 Intermediate Economics

    v.to increase or become successful very quickly.

    v.to experience rapid growth, success, or prosperity. Often used intransitively in economic contexts.

    Simple

    Business started to boom after the company launched its new website.

    In context

    The local tourism industry began to boom once the international airport was completed, bringing in thousands of visitors each week.

  5. 05 B2 Upper Intermediate

    v.to speak in a very loud and deep voice.

    v.to speak or shout with a deep, resonant, and powerful tone.

    Simple

    Get out of here, the old man boomed from the top of the stairs.

    In context

    The chairman's voice boomed across the hall, easily drowning out the murmurs of the dissatisfied shareholders.

    thunderbellowroar
  6. 06 B1 Intermediate Informal

    interj.a word used to show that something happened suddenly or successfully.

    interj.used to indicate a sudden occurrence, a successful completion, or a surprising revelation.

    Simple

    You just plug it in, press this button, and boom, it works.

    In context

    He made one final adjustment to the code and boom, the entire system was back online.

    voilapresto

Having moved quickly into the ready-to-drink market as it boomed following the pandemic, Au Vodka became second only to BuzzBallz in the UK.

BBC News· 17 Aug 2026

This play arrives at a time when Japanese culture is experiencing a global boom, particularly in London.

The Guardian· 14 Aug 2026

Etymology 1

Onomatopoeic, perhaps borrowed; compare German bummen, Dutch bommen (“to hum, buzz”). The sense "a period of economic growth" is generally taken to derive from the sense "a rapid expansion", although other origins have also been suggested.

Etymology 2

Borrowed from Dutch boom (“tree; pole”). Doublet of beam.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Dutch bommen
Level C1 · Advanced
Frequency Common
Updated