Definition of "thermonuclear" [thermonuclear]

• Of, relating to, or derived from the fusion of atomic nuclei at high temperatures: thermonuclear reactions. (adjective)
• Of, relating to, or characterized by the use of atomic weapons based on fusion, especially as distinguished from those based on fission: thermonuclear war. (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.

• "The facility also separates lithium-6 from natural lithium for use in thermonuclear weapons."
• "The implications of failure, resulting in thermonuclear exchange between the two superpowers during the Cold War, were horrendous."
• "And as he found out the back door he chose a game called thermonuclear war."