lethal radioactive fallout; atomic dust
Refers specifically to the deadly radioactive particles that fall after a nuclear explosion. Often used in historical or anti-nuclear contexts.
The lethal radioactive fallout caused enormous damage in Hiroshima and Nagasaki.
Atomic dust from the nuclear test was carried far away by the wind.
Compound of 死 (death) + の (possessive particle) + 灰 (ash). Literally 'ashes of death', a vivid metaphor for radioactive fallout.