noun
nadir
NAY-deer/ˈneɪdɪr/
The point in the sky directly beneath an observer.
The gold dot marks the nadir directly beneath the observer.

Etymology
Arabic nazir meant 'opposite,' referring here to the celestial point opposite the zenith, directly below the observer. That astronomical low point became a figurative lowest or worst state.
In context
many of our patients with rfid and anorexia any restrictive eating disorder have bumps in their lfts if it's present on admission when they're at their nadir of their weight loss then it's starvation mediated
More examples
- In this diagram, the nadir appears below the observer's feet.
- A line from the observer toward the nadir passes through Earth.
- As you move around Earth, your nadir changes with your position.
Forms
nadir · nadirs