The opposite of zenith (high point, apex) would be nadir(lowest point).
Other possible antonyms would be minimum or bottom.
In astronomical terms, the point in the sky that is directly over your head is the 'zenith'. The point in the sky that is directly between your feet and down through the Earth is the 'nadir'.
The zenith.
The ZENITH .
Zenith - watchmaker - was created in 1865.
During the equinoxes, when the Sun is at its highest, it will be at a distance from the zenith which is the same as your geographical latitude, but in the opposite direction. For example, if you live 50 degrees north of the equator, the Sun will be 50 degrees south of the zenith at noon.
Defining true zenith distance is knowing the difference between Africa and south America.True zenith distance is associated with Greenwich line and meridional zenith distance is defined with the celestial equator which instructs the basin of south america. -AG
The opposite of apex is antapex.(Nadir is the opposite of one use of apex, to mean zenith.)
The Igbo meaning for the word Zenith is "Elu elu."
Nadir comes for the arabic nazir, meaning opposite. Nadir is the direction directly below a point. It is in a way the opposite to Zenith. The word is also used in the meaning of the lowest point.
zenith
That's the observer's 'zenith'. Since it's referenced to the "observer's head", each observer has a different zenith.
The word "nadir" comes from Arabic "nadir," meaning "opposite." It was borrowed into English from Medieval Latin in the 14th century. In astronomy, nadir is the point on the celestial sphere opposite the zenith and directly below the observer.
zenith
"Nadir" is the point below you - the point opposite to the zenith.
"Picture a mountain peak" is a good way to remember the definition for zenith.
Translation: Awj (أوج) The English word Zenith is a derivative of the Arabic word "sama" by way of French. Sama can mean zenith as well, but more often means "symbol" or "stamp" than the "uppermost point".
zenith
Zenith