Propagation /(?)/

Prop·a·ga·tion

Propagation

n.
  1. The act of propagating; continuance or multiplication of the kind by generation or successive production; as, the propagation of animals or plants.
    There is not in nature any spontaneous generation, but all come by propagation.
  2. The spreading abroad, or extension, of anything; diffusion; dissemination; as, the propagation of sound; the propagation of the gospel.