Definitions of volume:

• noun:   the magnitude of sound (usually in a specified direction)

  Example: "The kids played their music at full volume"

• noun:   a publication that is one of a set of several similar publications

  Example: "The third volume was missing"

• noun:   the amount of 3-dimensional space occupied by an object

  Example: "The gas expanded to twice its original volume"

• noun:   a relative amount

  Example: "Mix one volume of the solution with ten volumes of water"

• noun:   physical objects consisting of a number of pages bound together
• noun:   the property of something that is great in magnitude

  Example: "The volume of exports"