ENGLISH
REFERENCE

killer

n. · adj.
US //ˈkɪɫɝ// UK //kˈɪlɐ// killer
  1. 1 one who kills (n.)
    A2 Elementary

    a person, animal, or thing that causes death.

    a person, animal, or agent that causes the death of another living being.

    Example

    The police are still searching for the killer after the attack.

    Example

    The documentary explores how the invasive species became a silent killer of the local bird population within just a few years.
  2. 2 something very difficult (n.)
    B2 Upper Intermediate Informal

    something that is extremely hard to do or causes a lot of stress.

    a task, situation, or experience that is exceptionally taxing or difficult to endure.

    Example

    That three-hour exam was a real killer.

    Example

    The final climb of the race is a absolute killer, forcing even the most seasoned cyclists to push their physical limits.
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  1. 3 killer whale (n.)
    B1 Intermediate Science

    another name for an orca.

    a common shorthand for the orca (Orcinus orca).

    Example

    We saw a pod of killer whales swimming near the boat.

    Example

    Marine biologists observed the killer whales using sophisticated hunting techniques to isolate their prey from the rest of the pod.
    • orca
  2. 4 excellent or impressive (adj.)
    B2 Upper Intermediate Slang

    very impressive, effective, or cool.

    strikingly effective, impressive, or fashionable. Often used in marketing or casual praise.

    Example

    She gave a killer presentation that convinced the whole board.

    Example

    The startup's new app features a killer interface that sets it apart from every other competitor in the crowded fintech market.
  3. 5 causing death (adj.)
    B2 Upper Intermediate

    deadly or very dangerous.

    having the capacity or tendency to cause death or total destruction.

    Example

    The city was hit by a killer heatwave last summer.

    Example

    The researchers identified a killer strain of the virus that appeared resistant to conventional antibiotic treatments.
Origin

From Middle English killer, kyller. By surface analysis, kill + -er.

Word family
Idioms4 entries

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