Definitions
1.NounSevere overheating of the core of a nuclear reactor resulting in the core melting and potentially in radiation escaping.
2.NounA situation being likened to a nuclear meltdown; a crisis.
3.NounA tantrum or emotional outburst.
4.NounAn autistic response to stress or sensory overload, in which the person is overwhelmed by intense, seemingly disproportionate emotions, behaving erratically and becoming unable to mask.