Biorhythm (noun)

A supposed rhythm or cycle in the physiological or psychological processes of living organisms.

Origin:

From bio- ("life") + -rhythm.

Examples:

1. The biorhythm theory suggests that a person's physical, emotional and intellectual abilities are influenced by regular cycles.
2. He checked his biorhythm chart to see if it was a good day for a job interview.
3. Some people believe that biorhythms can predict a person's luck or success in different areas of life.
4. The biorhythm theory is based on the idea that there are three fundamental cycles: physical, emotional and intellectual.
5. Many people use biorhythm charts to plan their daily activities for optimal performance.