n. pl. e·phem·er·a (-ər-ə) or e·phem·er·ons
1. A short-lived thing.
2. ephemera Printed matter of passing interest.
[Greek ephēmeron, mayfly, from neuter of ephēmeros, daily, short-lived; see EPHEMERAL.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.