rock flour

noun

Definition of rock flour

: finely powdered rock material produced by grinding action (as of a glacier on its bed)

called also glacial meal

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!

Learn More about rock flour

Statistics for rock flour

Cite this Entry

“Rock flour.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/rock%20flour. Accessed 10 December 2019.

Comments on rock flour

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

WORD OF THE DAY

to state or do over again or repeatedly

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?

TAKE THE QUIZ
Syn City

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

TAKE THE QUIZ
Love words? Need even more definitions?

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