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.

(figurative) 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.

(transitive, beekeeping) To extend (a beehive) by adding an empty box at the base.