What is "ephemera"? And how do you pronounce it, anyway? Ephemera (pronounced: "i-FEM-ur-uh"), refers to anything short-lived. Today we may be more familiar with the adjective, "ephemeral," used to describe fresh-cut flowers, a misty morning, or the rapidly changing colors of a fading sunset. But the noun, used in a library or archives setting, more often refers to two-dimensional objects, usually made out of paper, designed for limited use, often for just one day.