[thur-moh-noo-klee-er, -nyoo- or, by metathesis, -kyuh-ler]


of, relating to, or involving a thermonuclear reaction: thermonuclear power.

Origin of thermonuclear

First recorded in 1935–40; thermo- + nuclear

Pronunciation note

See nuclear. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for thermonuclear

thermonuclear, fissionable

Examples from the Web for thermonuclear

Contemporary Examples of thermonuclear

Historical Examples of thermonuclear

  • Malone doubted that the aborigine knew anything about thermonuclear processes, but he could start a fire with them.

    Occasion for Disaster

    Gordon Randall Garrett

  • In that year, too, tests were made at Eniwetok preliminary to the detonation of the first thermonuclear device.

  • Thermonuclear weapons, complemented over time by strong conventional forces, threatened societal damage to Russia.

    Shock and Awe

    Harlan K. Ullman

  • It also included immersion in technology and systems from thermonuclear weapons to advanced weapons software.

    Shock and Awe

    Harlan K. Ullman

  • And Blanley College was at the center of one of the areas which would receive the worst of the thermonuclear hell to come.

    The Edge of the Knife

    Henry Beam Piper

British Dictionary definitions for thermonuclear



involving nuclear fusiona thermonuclear reaction; thermonuclear energy
involving thermonuclear weaponsa 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

Word Origin and History for thermonuclear

1938 with reference to stars, 1953 of weapons (technically only to describe the hydrogen bomb), from thermo- + nuclear.

Online Etymology Dictionary, © 2010 Douglas Harper

thermonuclear in Science



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

thermonuclear in Culture


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.