Emily Dickinson Lexicon

E-PHEM'E-RA, n. [L. from Gr. εφημερος, daily; επι and ἡμερα, a day.]

1. A fever of one day's continuance only.
2. The day-fly; strictly, a fly that lives one day only; but the word is applied also to insects that are very short lived, whether they live several days or an hour only. There are several species.