What does thermonuclear mean?
Thermonuclear is an adjective describing nuclear reactions that require extremely high temperatures, especially the fusion of atomic nuclei. In everyday use, the word is strongly associated with thermonuclear weapons, including hydrogen bombs, and with the possibility of thermonuclear war. Its dramatic associations also make it useful in political and military language, where it can emphasize the scale of a threat or the destructive consequences of a conflict. In science and energy discussions, thermonuclear usually refers to fusion, the process that powers the Sun and that researchers are pursuing as a source of potentially abundant, low-carbon energy. The word combines thermo-, meaning “heat,” with nuclear, indicating the involvement of atomic nuclei. Unlike the broader term atomic, thermonuclear specifically points to reactions associated with extreme temperatures and fusion.
adjectiveThermonuclear means relating to or involving nuclear reactions, especially fusion, produced by extremely high temperatures. The term is especially associated with thermonuclear weapons and, in scientific contexts, thermonuclear fusion.
- Relating to or involving nuclear reactions, especially fusion, caused by extremely high temperatures.
- Relating to weapons or warfare employing thermonuclear reactions.
"The treaty aimed to reduce the threat of thermonuclear war."
"The treaty aimed to reduce the threat of thermonuclear war."
"Scientists are researching thermonuclear fusion as a possible source of clean energy."
Thermonuclear power turns the temperature of a star into a weapon—or, potentially, a nearly limitless energy source.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does thermonuclear come from?
The word is formed from the combining form thermo-, derived from Greek thermos, meaning “hot” or “heat,” and nuclear, from Latin nucleus, meaning “kernel” or “nut.” The two elements were combined in the 20th century to describe high-temperature nuclear processes, particularly fusion. Its related terms preserve the same historical roots: thermal and thermometer belong to the “heat” family, while nuclear and nucleus derive from the Latin word for a central kernel.
How thermonuclear is actually used
The word is common in technical, military, and political contexts. In discussions of energy, it usually refers to controlled fusion, while in discussions of warfare it often carries connotations of extreme destructive power and global catastrophe.
Easily confused with thermonuclear
Atomic refers broadly to atoms and is often used for fission weapons, whereas thermonuclear specifically refers to fusion or other nuclear reactions involving extremely high temperatures.