blue·​schist | \ ˈblü-ˌshist \
plural blueschists

Definition of blueschist

geology : a metamorphic rock that is formed under high pressure and low temperature and is characterized by the presence of glaucophane Also radiometric ages of blueschists from the same regions cluster around 400-500 Myr.— T. Nakajima et al., Nature, 19 July 1990 At this depth, where the pressure is 15 to 20 kilobars and temperatures reach about 500 degrees C, rocks called blueschists and eclogites form.— Ian Anderson, New Scientist, 29 Mar. 1997

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!

First Known Use of blueschist

1789, in the meaning defined above

Keep scrolling for more

Learn More about blueschist

Share blueschist

Statistics for blueschist

Look-up Popularity

Time Traveler for blueschist

The first known use of blueschist was in 1789

See more words from the same year

Comments on blueschist

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


a servile follower or underling

Get Word of the Day daily email!

Test Your Vocabulary

What did you just call me?! A Quiz

  • rows-of-various-emoji
  • If a member of the audience describes your speech as bombastic, does that person mean it is:
Name That Thing

Test your visual vocabulary with our 10-question challenge!


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!