noun
atomic age; atomic era
Refers to the historical period beginning with the development and use of atomic weapons and nuclear energy, often associated with the mid-20th century onward.
原子時代の到来は世界を大きく変えた。
The arrival of the atomic age changed the world dramatically.
Compound of 原子 (genshi, 'atom') and 時代 (jidai, 'era, age').