What's the noun for nadired? Here's the word you're looking for.
nadir
The point of the celestial sphere, directly opposite the zenith; inferior pole of the horizon; point of the celestial sphere directly under the place where we stand.
(figuratively) The lowest point; time of greatest depression.
(astronomy) The axis of a projected conical shadow; the direction of the force of gravity at a location; down.
(beekeeping, archaic) An empty box added beneath a full one in a beehive to give the colony more room to expand or store honey.