meltdown

Noun

meltdown (countable and uncountable, plural meltdowns)

1. (countable) An act or process of melting.
   1. (uncountable, nuclear energy) Severe uncontrolled overheating and melting of the fuel in the core of a nuclear reactor, with the potential for radiation to escape; (countable) an instance of this.
      • Thus began by far the gravest crisis in the troubled, 32-year history of commercial atomic power. A catastrophe had occurred over the weekend at the Chernobyl plant, 80 miles north of Kiev, where a reactor meltdown and explosion caused untold death and suffering and raised the prospect of long-term...1986 May 12, John Greenwald, “Deadly Meltdown”, in Time, New York, N.Y.: Time Inc., →ISSN, →OCLC, archived from the original on 21 May 2025
2. (countable, rare) A mass of melted material.
3. (figuratively, uncountable) Chiefly preceded by a descriptive word: uncontrolled disorder which often has disastrous consequences; (countable) a situation involving this; a crisis.
   • Channel 4 switchboards went into meltdown this week when viewers called to complain about a Brass Eye programme on child sex.2001, James Wickham, “Perv spoof bosses axe wrestling”, in Peter Hill, editor, Daily Star, London: Reach plc, →ISSN, →OCLC, column 1
   • Computer engineers were at a loss last night to explain why the Government had been hit by arguably the worst electronic meltdown in the history of Whitehall.2004 November 27, Barrie Clement, “Computer meltdown baffles the experts”, in The Independent, London: Independent News & Media, →ISSN, →OCLC, archived from the original on 09 Dec 2004
   1. (countable, figuratively) Synonym of crash (“a sudden large decline in the value of money, stocks or other assets, etc., especially one that causes additional economic difficulties”).
4. (countable, figuratively, informal) An emotional outburst; a fit, a tantrum.

   Synonyms:

   melty, tantrum, catfit, conniption, conniption fit, dummy spit, headfit, hissy, hissy fit, paddy

5. (countable, figuratively, informal, autism) A response to sensory overload or stress, in which an autistic person is overwhelmed by intense, seemingly disproportionate emotions, behaving erratically and becoming unable to mask (“act more neurotypically”).
   • I was diagnosed with Asperger's syndrome in my forties. […] Now if I am really anxious, I can take a moment to think about what is making me anxious and what to do about it; before I would just spiral into a meltdown really quickly, with no understanding of why.2016, Jeanette Purkis, Emma Goodall, Jane Nugent, quoting Laura, “Diagnosis”, in The Guide to Good Mental Health on the Autism Spectrum, London; Philadelphia, Pa.: Jessica Kingsley Publishers, →ISBN...
   • As the brain starts becoming overwhelmed with stress chemicals, it has two primary ways of responding. […] [I]f the accumulation of stress chemicals, stimulation and/or demands are occurring too fast or are too intense to block out, then a meltdown is probable.2020, Bill Nason, “Shutdowns and Meltdowns”, in The Autism Discussion Page on Stress, Anxiety, Shutdowns and Meltdowns: Proactive Strategies for Minimizing Sensory, Social and Emotional Overload...

   Synonyms:

   melty

6. (countable, figuratively, informal) Synonym of nervous breakdown (“an attack of a psychological disorder such as anxiety or depression which is so severe that it prevents a person from continuing to function normally”); also (loosely), a situation where one is unable to function mentally due to panic, stress, etc.
   • I had a major meltdown at work today. After being instructed one more time about additional work that I was to delegate to my direct reports, I snapped, but in a very polite manner. I excused myself from the boss' office and broke down completely in my cubicle.2006, Ercille Christmas, “Thursday, 7/11/02”, in Thoughts of a Proud American: An Ode to “Joe and Josephine Ordinary, Salt of the Earth Americans”, Bloomington, Ind.; Milton Keynes, Buckinghamshire...
   • After the huntsman raced across my windscreen, I had an arachnophobic meltdown on the side of the road.2025 January 27, Alexandra Carlton, “The kindness of strangers: I pulled over in hysterics – then a passing driver saved me from the spider”, in Katharine Viner, editor, The Guardian, London...

   Synonyms:

   melty, mental breakdown, nervous breakdown