The Collaborative International Dictionary of English v.0.48:

Dropping \Drop"ping\, n.
   1. The action of causing to drop or of letting drop; falling.
      [1913 Webster]

   2. pl. That which falls in drops; the excrement or dung of
      animals; -- often used in the plural.
      [1913 Webster]

   Dropping bottle, an instrument used to supply small
      quantities of a fluid to a test tube or other vessel.

   Dropping fire, a continued irregular discharge of firearms.


   Dropping tube, a tube for ejecting any liquid in drops.
      [1913 Webster]