The axis of a projected conical shadow; the direction of the force of gravity at a location; down.
The lowest point; time of greatest depression.
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.
To extend (a beehive) by adding an empty box at the base.
The side which is not normally seen, normally a dark, immoral place.
The underside of any thing.
The underside of an animal.