to·​ka·​mak | \ ˈtō-kə-ˌmak How to pronounce tokamak (audio) , ˈtä- How to pronounce tokamak (audio) \
variants: or less commonly tokomak

Definition of tokamak

: a toroidal device for producing controlled nuclear fusion that involves the confining and heating of a gaseous plasma by means of an electric current and magnetic field

Examples of tokamak in a Sentence

Recent Examples on the Web In 2018, the tokamak reached 180 million degrees Fahrenheit, or about 82 million degrees Celsius. Caroline Delbert, Popular Mechanics, 7 June 2021 Could the future of nuclear fusion be a much smaller, self-sustaining tokamak reactor? Caroline Delbert, Popular Mechanics, 5 Apr. 2021 Where did the compact advanced tokamak design concept come from? Caroline Delbert, Popular Mechanics, 5 Apr. 2021 The tokamak chamber, seen from the top (top) and middle (bottom), is a cylinder that will hold the ITER experiment. Clara Moskowitz, Scientific American, 1 Dec. 2020 Like a tokamak, an MTF reactor involves hot plasma contained by a powerful magnetic field. Caroline Delbert, Popular Mechanics, 25 Jan. 2021 Like many of the world’s tokamak experiments, EAST has reached fusion before. Caroline Delbert, Popular Mechanics, 4 Dec. 2020 But no tokamak has generated more energy from fusion than is used to heat up the plasma. Daniel Clery, Science | AAAS, 2 Dec. 2020 The scientists also replaced the entire exhaust system, which in a tokamak is an especially vulnerable part. Caroline Delbert, Popular Mechanics, 9 Nov. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tokamak.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of tokamak

1965, in the meaning defined above

History and Etymology for tokamak

Russian, from toroidal'naya kamera s aksial'nym magnitnym polem (toroidal chamber with an axial magnetic field)

Keep scrolling for more

Learn More About tokamak

Time Traveler for tokamak

Time Traveler

The first known use of tokamak was in 1965

See more words from the same year

Dictionary Entries Near tokamak





Tokara Islands



See More Nearby Entries 

Statistics for tokamak

Last Updated

15 Jun 2021

Cite this Entry

“Tokamak.” Dictionary, Merriam-Webster, Accessed 24 Jun. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More from Merriam-Webster on tokamak Encyclopedia article about tokamak


Test Your Vocabulary

Return of Name that Color!

  • a light greenish blue color
  • Name that color:
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!