[ thur-moh-noo-klee-er, -nyoo- or, by metathesis, -kyuh-ler ]
/ ˌθɜr moʊˈnu kli ər, -ˈnyu- or, by metathesis, -kyə lər /


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


Nearby words

  1. thermometric titration,
  2. thermometry,
  3. thermomotive,
  4. thermomotor,
  5. thermonasty,
  6. thermonuclear bomb,
  7. thermonuclear reaction,
  8. thermopane,
  9. thermoperiodic,
  10. thermoperiodicity

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

Examples from the Web for thermonuclear

British Dictionary definitions for thermonuclear


/ (ˌθɜːməʊˈnjuːklɪə) /


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

Science definitions for thermonuclear


[ thûr′mō-nōōklē-ər ]

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.

Culture 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.