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1. Relating to or occurring in a 24-hour period; daily.
2. Occurring or active during the daytime rather than at night: diurnal animals.
3. Botany Opening during daylight hours and closing at night.
1. A book containing all the offices for the daily canonical hours of prayer except matins.
2. Archaic
a. A diary or journal.
b. A daily newspaper.

[Middle English, from Late Latin diurnālis, from Latin diurnus, from diēs, day; see dyeu- in Indo-European roots.]

di·ur′nal·ly adv.
References in classic literature ?
in imitation of the tone in which that useful class of society are wont, diurnally, to make their presence known at area railings.
Prevalence of diurnally susperiodic bancroftian filariasis among the Nicobarese in Andaman and Nicobar Islands India: effect of age and gender.
This pattern of diurnally larger catches was also exhibited by four out of six flatfish species examined (Table 1, Fig.
In practice, growing chickens are subjected to a wide range of diurnally cycling temperatures rather than a constant one.
Furthermore, the use of MPC in buildings with a data-driven perspective should rely on variables that vary diurnally, and thus, reduce the prediction task difficulty (i.
2] Number of 21 floors 3 floors 5 floors Floors Year 2007 2000 1999-2000 Number of 2 recips 1 turbine 1 turbine Movers Number of none 2 2 Boilers Chillers 2+1 1+1 - VC+AC Number of 18 24 6 Combinations Electric TOU (vary both TOU (vary diurnally TOU (ete over Price diurnally and but not seasonally) day and seasonally) season) Gas Price 8.
Pelagic shrimps concentrate in the deep scattering layer and diurnally migrate in the water column.
The ammoxenids are able to detect these bursts whether they occur nocturnally or diurnally (Wilson & Clark 1977; Dippenaar-Schoeman et al.
PLANTS VARY DIURNALLY in concentrations of nonstructural carbohydrates with greatest concentrations observed in the afternoon (Bowden et al.
Figure 1 gives an indication of how ozone varies diurnally by graphing the amounts of ozone by hour of the day.
Over 3 times as many encounters occurred nocturnally (n = 661) than diurnally (n = 182) at both the viewing and control sites (Figs.
2] exchange in our study was measured both diurnally and seasonally on the same parcel of ground over time (n = 3 per treatment per site).