meltdown

[ melt-doun ]
/ ˈmɛltˌdaʊn /

noun

the melting of a significant portion of a nuclear-reactor core due to inadequate cooling of the fuel elements, a condition that could lead to the escape of radiation.
a quickly developing breakdown or collapse: a bond-market meltdown; the meltdown of a marriage.
Informal. a sudden loss of control over one’s feelings or behavior: My toddler had a meltdown when I tried to leave the house.

Origin of meltdown

First recorded in 1960–65; noun use of verb phrase melt down
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for meltdown

British Dictionary definitions for meltdown

meltdown

/ (ˈmɛltˌdaʊn) /

noun

(in a nuclear reactor) the melting of the fuel rods as a result of a defect in the cooling system, with the possible escape of radiation into the environment
informal a sudden disastrous failure with potential for widespread harm, as a stock-exchange crash
informal the process or state of irreversible breakdown or declinethe community is slowly going into meltdown
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for meltdown

meltdown

[ mĕltdoun′ ]

Severe overheating of a nuclear reactor core, resulting in melting of the core and escape of radiation.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for meltdown

meltdown


The most serious accident that can occur at a nuclear reactor. In a meltdown, the radioactive material in the reactor becomes very hot, melting some or all of the fuel in the reactor. A meltdown may or may not be followed by the release of radioactive material to the environment. A partial meltdown, with very little external radiation, occurred at Three Mile Island (see also Three Mile Island) in 1979; a complete meltdown happened at Chernobyl in 1986.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.