Main Entry: nu·cle·ar

Pronunciation: \ˈnü-klē-ər, ˈnyü-, ÷-kyə-lər\

Function: adjective

Date: 1846

1 : of, relating to, or constituting a nucleus
2 a : of or relating to the atomic nucleus <nuclear reaction> <nuclear physics> b : used in or produced by a nuclear reaction (as fission) <nuclear fuel> <nuclear waste> <nuclear energy> c (1) : being a weapon whose destructive power derives from an uncontrolled nuclear reaction (2) : of, produced by, or involving nuclear weapons <the nuclear age> <nuclear war> (3) : armed with nuclear weapons <nuclear powers> d : of, relating to, or powered by nuclear energy <a nuclear submarine> <the nuclear debate> <a nuclear plant>
3 : crazy, berserk —usually used in the phrase go nuclear

usage Though disapproved of by many, pronunciations ending in \-kyə-lər\ have been found in widespread use among educated speakers including scientists, lawyers, professors, congressmen, United States cabinet members, and at least two United States presidents and one vice president. While most common in the United States, these pronunciations have also been heard from British and Canadian speakers.