nadir

Short definition from Wiktionary

Noun

1. 1
   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.
2. 2
   The lowest point; time of greatest depression.
3. 3
   The axis of a projected conical shadow; the direction of the force of gravity at a location; down.
4. 4
   An empty box added beneath a full one in a beehive to give the colony more room to expand or store honey.

Verb

1. 1
   To extend (a beehive) by adding an empty box at the base.

Proper noun

1. 1
   A male given name.
2. 2
   A surname.