epi·​thermal | \ ¦epə̇, ¦epē+ \

Definition of epithermal

1 : deposited from warm waters at rather shallow depth under conditions in the lower ranges of temperature and pressure used of mineral veins and ore deposits — compare hypothermal, mesothermal
2 : having translational speeds and energies greater than those usually due to thermal agitation but less than those required for nuclear fission epithermal neutrons

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for epithermal

epi- + thermal

Keep scrolling for more

Learn More about epithermal

Statistics for epithermal

Cite this Entry

“Epithermal.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/epithermal. Accessed 7 December 2019.

Comments on epithermal

What made you want to look up epithermal? Please tell us where you read or heard it (including the quote, if possible).


the study of flags

Get Word of the Day daily email!

Test Your Vocabulary

Semantic Drift Quiz

  • a twisty river
  • Which of the following was once a synonym for fun?
Spell It

Can you spell these 10 commonly misspelled words?

Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

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