propagation

Multiplication or increase, as by natural reproduction.

The process of spreading to a larger area or greater number; dissemination.

The act or process of propagating, especially the process by which a disturbance, such as the motion of electromagnetic or sound waves, is transmitted through a medium such as air or water.

The act of propagating; the multiplication or continuance of the kind or species by natural generation or reproduction.

The spreading or extension of anything; diffusion.