[ ih-fem-er-uh ]
/ ɪˈfɛm ər ə /

noun, plural e·phem·er·as, e·phem·er·ae [ih-fem-uh-ree] /ɪˈfɛm əˌri/ for 2.

a plural of ephemeron.
an ephemerid.

Nearby words

  1. ephebic,
  2. ephebus,
  3. ephedra,
  4. ephedrine,
  5. ephelis,
  6. ephemeral,
  7. ephemerality,
  8. ephemerid,
  9. ephemeris,
  10. ephemeris second

Origin of ephemera

1670–80; < Greek ephḗmera, neuter plural of ephḗmeros, taken as singular; see ephemeral

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ephemerae

British Dictionary definitions for ephemerae


/ (ɪˈfɛmərə) /

noun plural -eras or -erae (-əˌriː)

a mayfly, esp one of the genus Ephemera
something transitory or short-lived
(functioning as plural) a class of collectable items not originally intended to last for more than a short time, such as tickets, posters, postcards, or labels
a plural of ephemeron

Word Origin for ephemera

C16; see ephemeral

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ephemerae



late 14c., originally a medical term, from Medieval Latin ephemera (febris) "(fever) lasting a day," from fem. of ephemerus, from Greek ephemeros "lasting only one day, short-lived," from epi "on" (see epi-) + hemerai, dative of hemera "day," from PIE *amer- "day."

Sense extended 17c. to short-lived insects and flowers; general sense of "thing of transitory existence" is first attested 1751. Cf. Greek ephemeroi "men," literally "creatures of a day."

Online Etymology Dictionary, © 2010 Douglas Harper