ENGLISH
REFERENCE

meltdown

n.
US //ˈmɛɫtˌdaʊn// UK //mˈɛltdaʊn// melt·down
  1. 1 nuclear failure (n.)
    B2 Upper Intermediate Technical Science

    a very dangerous accident where the center of a nuclear power plant gets too hot and melts.

    the melting of a nuclear reactor core due to a failure of the cooling system, often leading to the release of radiation.

    Example

    The safety systems prevented a total meltdown after the earthquake damaged the power plant.

    Example

    Engineers worked around the clock to prevent a full-scale meltdown, as the rising temperatures in the reactor core threatened the containment structure.

    Usage

    Often used with 'nuclear' or 'reactor'.

    • nuclear accident
    • core melt
  2. 2 emotional outburst (n.)
    B2 Upper Intermediate Informal Psychology

    a sudden loss of control over your feelings, often involving crying or shouting because of too much stress.

    an episode of intense emotional distress or a loss of self-control, frequently triggered by overwhelming stress or sensory overload.

    Example

    The toddler had a complete meltdown in the supermarket because he couldn't have the toy.

    Example

    After weeks of working overtime without a break, he suffered a public meltdown during the board meeting.

    Teacher's tip

    While often used for children's tantrums, in a psychological context it specifically describes an involuntary response to being overwhelmed.

  3. 3 economic or systemic crash (n.)
    C1 Advanced Academic Formal

    a sudden and complete failure of a system, like the stock market or a large company.

    a sudden, disastrous collapse of a financial or social system.

    Example

    The global financial meltdown of 2008 affected millions of homeowners.

    Example

    Economists warned that a sudden increase in interest rates could trigger a market meltdown, destabilizing the fragile recovery.

Origin

Deverbal from melt down.

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

Last updated June 20, 2026