[ thur-moh-noo-klee-er, -nyoo- or, by metathesis, -kyuh-ler ]
See synonyms for thermonuclear on
  1. of, relating to, or involving a thermonuclear reaction: thermonuclear power.

Origin of thermonuclear

First recorded in 1935–40; thermo- + nuclear

pronunciation note For thermonuclear

See nuclear.

Words Nearby thermonuclear Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use thermonuclear in a sentence

British Dictionary definitions for thermonuclear


/ (ˌθɜːməʊˈnjuːklɪə) /

  1. involving nuclear fusion: a thermonuclear reaction; thermonuclear energy

  2. involving thermonuclear weapons: a thermonuclear war

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for thermonuclear


[ thûr′mō-nōōklē-ər ]

  1. Relating to the fusion of atomic nuclei at high temperatures or to the energy produced in this way.

  2. Relating to weapons based on nuclear fusion, especially as distinguished from those based on nuclear fission.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for thermonuclear


A term referring to devices that use nuclear fusion, the fusion of atomic nuclei, to produce energy at very high temperatures. (See hydrogen bomb.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.