nadir UK /ˈneɪˌdɪə(ɹ)/US /ˈneɪˌdɪɚ/noun 4verb 1forms 3 noun4 •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.[…] when we are Nadyr to the Sunne, we have no shadow […] — 1638 •(figurative) The lowest point; time of greatest depression.[…] the seventh century is the nadir of the human mind in Europe […] — 1837 •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. •(no longer used) An empty box added beneath a full one in a beehive to give the colony more room to expand or store honey. verb1 •To extend (a beehive) by adding an empty box at the base. formsnadired · nadiring · nadirs