autolith

noun

au·​to·​lith

plural -s

: a fragment of a previously crystallized portion of rock enclosed in material from the same magma which solidified later

Word History

Etymology

aut- + -lith

First Known Use

1900, in the meaning defined above

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!