From Longman Dictionary of Contemporary Englishatomic bombaˌtomic ˈbomb (also atom bomb) noun [countable] PMWa nuclear bomb that splits atoms to cause an extremely large explosion
Examples from the Corpus
atomic bomb• This is the essence of an atomic bomb.• The Enola Gay dropped the first atomic bomb on Hiroshima at 8: 15 in the morning of August 6,1945.• Then came the successful test of the first atomic bomb.• For comparison, the atomic bomb explosions that devastated Hiroshima and Nagasaki were about 20 kilotons each.• U.S. policymakers eliminated both points, however, once the atomic bomb was tested.• This impasse applied especially to the atomic bomb.• The atomic bomb had the great advantage of being cheaper than mass armies-and much quicker. 