ephemera [LME] An ephemera or ephemeron was originally a fever lasting only one day, an insect with a very short lifespan, or a plant thought to last a day. Some ancient writers thought there were two plants of this name, one that sprang up and died in a day, the other that carried a poison causing death within a day. The word was then applied to a person or thing of short-lived interest. It appeared in its current plural sense in the 1930s, to describe items like tickets, posters, and greetings cards that were of no enduring value except to collectors. Ephemera and ephemeral [L16th] ‘lasting for a very short time’, are from Greek ephēmeros ‘lasting only a day’, from hēmera ‘day’.