EPHEM'ERA, noun [Latin from Gr. daily; a day.] A fever of one day's continuance only. 1. 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.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI