/ ɪˈfemərə; NAmE / noun
[ pl. ] things that are important or used for only a short period of time :
a collection of postcards, tickets and other ephemera
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WORD ORIGIN
late 16th cent.: plural of ephemeron , from Greek , neuter of ephēmeros lasting only a day. As a singular noun the word originally denoted a plant said by ancient writers to last only one day, or an insect with a short lifespan, and hence was applied (late 18th cent.) to a person or thing of short-lived interest. Current use has been influenced by plurals such as trivia and memorabilia .