Ephemera
Ephemera , noun
[New Latin, from Greek {not transcribed} a day fly, from {not transcribed} daily, lasting but a day; {not transcribed} over + {not transcribed} day.]
1.
(Medicine) A fever of one day's continuance only.
2.
(Zoology) A genus of insects including the day flies, or ephemeral flies. See Ephemeral fly, under Ephemeral.