diurnal; daily cycle
Technical prefix used in scientific or astronomical contexts to describe phenomena related to a 24-hour day, such as 日周運動 (diurnal motion).
Diurnal motion is caused by the Earth's rotation.
The diurnal rhythm of this organism is influenced by light.
Standard kanji spelling for this prefix.
Compound of 日 (sun, day) and 周 (cycle, circumference), literally 'day cycle'. The reading にっしゅう is a regular on'yomi combination.