zeitgeber n. a naturally occurring cue, such as light or temperature, which regulates biological rhythms; something which influences or regulates the timing or rhythm of something else. Etymological Note: zeit ‘time’ + geber ‘giver.’ Coined by Jürgen Aschoff, ca. 1954. (source: Double-Tongued Dictionary)
what does the biological organizion mean. I need a definnion of the word?