gneiss

noun

ˈnīs How to pronounce gneiss (audio)
: a foliated metamorphic rock corresponding in composition to a feldspathic plutonic rock (such as granite)
gneissic
ˈnī-sik How to pronounce gneiss (audio)
adjective
gneissoid
ˈnī-ˌsȯid How to pronounce gneiss (audio)
adjective
gneissose
ˈnī-ˌsōs How to pronounce gneiss (audio)
adjective

Examples of gneiss in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Feldspar and mica, the main minerals in plutonic rocks like granite and metamorphic rocks like gneiss and schist, react with water and oxygen, decaying to clay minerals. — David Bressan, Forbes, 31 Oct. 2024 The West Kootenay bouldering scene is arguably the fastest growing in Canada, with tons of high-quality gneiss and granite coupled with talented, motivated locals establishing new routes faster than anyone can document. — Jayme Moye, Outside Online, 4 Oct. 2024

Word History

Etymology

German Gneis, alteration of Middle High German gneiste spark, from Old High German gneisto; akin to Old English fȳrgnāst spark

First Known Use

1757, in the meaning defined above

Time Traveler
The first known use of gneiss was in 1757

Rhymes for gneiss

See All Rhymes for gneiss

Browse Nearby Words

gnd
gneiss
Gnesio-Lutheran
See all Nearby Words

Cite this Entry

“Gneiss.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/gneiss. Accessed 1 Apr. 2025.

Copy Citation

Share

Kids Definition

gneiss

noun
ˈnīs How to pronounce gneiss (audio)
: a rock in layers that is similar in composition to granite

More from Merriam-Webster on gneiss

Britannica.com: Encyclopedia article about gneiss

Love words? Need even more definitions?

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

Popular in Grammar & Usage

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

The Difference Between 'i.e.' and 'e.g.'

Why is '-ed' sometimes pronounced at the end of a word?

Words You Always Have to Look Up

Democracy or Republic: What's the difference?
See More

Popular in Wordplay

See More

What do SCOTUS, POTUS, and FLOTUS mean?

Top 10 Sophisticated Insults

More Words with Remarkable Origins

Terroir, Oenophile, & Magnum: Ten Words About Wine

8 Words for Lesser-Known Musical Instruments
See More

Popular

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

What do SCOTUS, POTUS, and FLOTUS mean?

Top 10 Sophisticated Insults
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Word Game Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
burrowing owl athene cunicularia tilts its head outside its burrow on marco island florida
Guess the Curious Origins of These Everyday Words Oh, that’s where that comes from…
See All