helioseismology

noun

he·​lio·​seis·​mol·​o·​gy ˌhē-lē-ō-sīz-ˈmä-lə-jē 

-sīs-

: the study of vibrations in the material that makes up the Sun

Scientists have discovered that the sun is vibrating, and they can detect this “global oscillation” using the new techniques of “helioseismology,” which are similar to those used in terrestrial seismology.

—Madeleine Jacobs, Chicago Tribune, 29 Dec. 1985

Word History

First Known Use

1979, 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!