jefferisite

noun

jef·​fer·​is·​ite

ˈjef(ə)rə̇ˌsīt

plural -s

: a mineral consisting of a vermiculite containing iron, aluminum, and magnesium

Word History

Etymology

William W. Jefferis †1906 American banker + English -ite

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!