# thermonuclear

/ˌθɝmoʊˈnukɫiɝ/ (US) · /θˈɜːmənjˌuːkliə/ (UK) · CEFR C2 · Adjective

Source: https://englishreference.com/word/thermonuclear
Updated: 2026-10-14

## Definition

relating to nuclear reactions that need extreme heat to release a huge amount of energy. You see it mostly in talk about powerful hydrogen bombs.

For teachers: relating to nuclear fusion reactions that occur at extremely high temperatures, releasing vast amounts of energy. Typically describes hydrogen bombs and stellar processes where light nuclei fuse.

## Examples

- This plant studies thermonuclear reactions for clean energy.
- Engineers test thermonuclear designs to understand how fusion releases so much energy.
- Physicists describe thermonuclear fusion in stars as a delicate balance where gravity confines plasma long enough for light nuclei to merge and sustain enormous energy output.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.