Ephemera are any transitory written or printed matters that are not meant to be retained or preserved. The word derives from the Greek ephemeros, meaning "lasting only one day, short-lived".
noun plural noun: ephemera; noun: ephemerum
things that exist or are used or enjoyed for only a short time. "there were papers, letters, old boxes—all sorts of ephemera"
Late 16th century: 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 century) to a person or thing of short-lived interest. Current use has been influenced by plurals such as trivia and memorabilia .