Definition of meltdown
1 : the accidental melting of the core of a nuclear reactor
2 : a rapid or disastrous decline or collapse
3 : a breakdown of self-control (as from fatigue or overstimulation)
Examples of meltdown in a Sentence
fears that an accident could cause meltdown
a company experiencing financial meltdown
After a long day at the beach, our toddler had a major meltdown in the car on the way home.
First Known Use of meltdown
MELTDOWN Defined for English Language Learners
Definition of meltdown for English Language Learners
: an accident in which the core of a nuclear reactor melts and releases radiation
: a very fast collapse or failure
: a very fast loss of emotional self-control
Seen and Heard
What made you want to look up meltdown? Please tell us where you read or heard it (including the quote, if possible).