internal clock

American  

noun

1. biological clock.

---

Etymology

Origin of internal clock

First recorded in 1955–60

Example Sentences

The findings suggest that manipulating the body's internal clock -- specifically by inhibiting REV-ERBα -- could represent a new way to protect the brain, prevent tau buildup, and potentially slow or halt the progression of Alzheimer's disease.

From Science Daily

My internal clock wherever I am just knows it’s 4 p.m. and I get a little sad.

From Los Angeles Times

When it is bright, our internal clock feels we should be awake.

From BBC

Additionally, disruptions to the body's internal clock can affect astronaut's sleeping and eating cycles.

From Salon

Prof Luscher said that - like the researchers suggest - it is "possible" that coffee drinking later in the day could disrupt out bodies internal clock at a time we should be resting.

From BBC