ephemera. ephemera | əˈfem(ə)rə | pluralnoun things that exist or are used or enjoyed for only a short time: there were papers, letters, old boxes—all sorts of ephemera. • items of collectible memorabilia, typically written or printed ones, that were originally expected to have only short-term usefulness or popularity: Mickey Mouse ephemera. ORIGINlate 16th century: pluralofephemeron, 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 century) to a person or thing of short-lived interest. Current use has been influenced by plurals such as trivia and memorabilia.