nadir
/neɪˈdɪə(ɹ)/
The point of the celestial sphere, directly opposite the zenith; inferior pole of the horizon; point of the celestial sphere directly under the place of observation.
The lowest point; time of greatest depression.
The axis of a projected conical shadow; the direction of the force of gravity at a location; down.
The nadir of the sun is the axis of the shadow projected by the Earth.
An empty box added beneath a full one in a beehive to give the colony more room to expand or store honey.