Of or employing nuclear energy: an atomic submarine; atomic weapons. (adjective)
Very small; infinitesimal. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "atomic" in a sentence
"For example, World War II was ending and you could easily use the term atomic bomb, which might be thought to be more important than show biz."
"Dalton's application of the Greek atomic theory to the facts established by the analyses of compounds enabled him to attach to each element a number which he called the atomic weight of the element, and to summarise all the facts concerning the compositions of compounds in the statement, that the elements combine in the ratios of their atomic weights, or in the ratios of whole multiples of their atomic weights."
"Helping the burn victims, doctors took some time to realize that they were dealing with a new and horrifically deadly phenomenon, radiation sickness—what they called atomic bomb disease."