1560s; see ephemera + -al (1). Originally of diseases and lifespans, "lasting but one day;" extended sense of "transitory" is from 1630s. Related: Ephemerally; ephemerality.
the ephemeral joys of childhood
ephebe
ephebic
ephedra
ephedrine
ephemera
ephemeral
ephemeris
ephemeron
Ephesians
Ephesus
ephialtes