- 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
WordReference Random House Unabridged Dictionary of American English © 2026
e•phem•er•a
(i fem′ər ə),USA pronunciation n., pl. -er•as, -er•ae (-ə rē′)USA pronunciation for 2.
- a pl. of ephemeron.
- Insectsan ephemerid.
- Greek ephé̄mera, neuter plural of ephé̄meros, taken as singular; see ephemeral
- 1670–80
Collins Concise English Dictionary © HarperCollins Publishers::
ephemera /ɪˈfɛmərə/ n ( pl -eras, -erae /-əˌriː/)
e•phem•er•on
(i fem′ə ron′, -ər ən),USA pronunciation n., pl. -er•a (-ər ə),USA pronunciation -er•ons.
- anything short-lived or ephemeral.
- ephemera, items designed to be useful or important for only a short time, esp. pamphlets, notices, tickets, etc.
- Greek ephé̄meron short-lived insect, noun, nominal use of neuter of ephé̄meros; see ephemeral
- 1570–80
'ephemera' also found in these entries (note: many are not synonyms or translations):