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REFERENCE

boom

n. · v. · interj.
US //ˈbum// UK //bˈuːm// boom
  1. 1 economic growth (n.)
    B1 Intermediate Economics

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

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

    Example

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

    Example

    Economists debated whether the current tech boom was a sustainable growth period or a speculative bubble destined to burst.
  2. 2 loud sound (n.)
    B2 Upper Intermediate

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

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

    Example

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

    Example

    The sonic boom shattered several windows in the village as the experimental jet exceeded the speed of sound.
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  1. 3 equipment pole (n.)
    C1 Advanced Technical

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

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

    Example

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

    Example

    The sailor swung the boom across the deck as the wind shifted, narrowly avoiding the passengers standing near the stern.
  2. 4 to grow quickly (v.)
    B1 Intermediate Economics

    to increase or become successful very quickly.

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

    Example

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

    Example

    The local tourism industry began to boom once the international airport was completed, bringing in thousands of visitors each week.
  3. 5 to speak loudly (v.)
    B2 Upper Intermediate

    to speak in a very loud and deep voice.

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

    Example

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

    Example

    The chairman's voice boomed across the hall, easily drowning out the murmurs of the dissatisfied shareholders.
  4. 6 sudden event (interj.)
    B1 Intermediate Informal

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

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

    Example

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

    Example

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

Idioms1 entry

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