Noah Webster
Diurnal
DIURNAL, adjective [Latin , daily.]
1. Relating to a day; pertaining to the daytime; as diurnal heat; diurnal hours.
2. Daily; happening every day; performed in a day; as a diurnal task.
3. Performed in 24 hours; as the diurnal revolution of the earth.
4. In medicine, an epithet of diseases whose exacerbations are in the day time; as a diurnal fever.
DIURNAL, noun A day-book; a journal. [See Journal, which is mostly used.]