from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An innate, cyclical biological process or function.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any cyclic biological or physiological pattern or activity
- n. Any of three sinusoidal graphs, normally plotted by computer, having a person's birth date as origin that that are supposed to give meaningful information about emotional levels, physical energy levels, and mental/psychic sensitivity.
First coined 1960, from bio- + rhythm (Wiktionary)