Zenith & Nadir
Zenith
- The point on the Celestial Sphere
directly above the observer. The zenith is diametrically
opposite to the nadir.
- In general, the highest state or point.
Originally derived from the Arabic semt ar-ras meaning way over the head:
ME senyth; ML cenit.
Source: Ba-1418.
Nadir
- The point on the Celestial Sphere
directly below the observer. The nadir is diametrically
opposite to the zenith.
- In general, the lowest state or point.
Originally derived from the Arabic nazir meaning the corresponding
opposite.
Source: Ba-806.