spillover

/S P IH1 L OW0 V ER0/
noun
  1. 1

    That which overflows; the excess or side effect.

    โ€œThe spillover from the dam due to the heavy rains will run down this channel and harmlessly dump into that river, we hope.โ€

  2. 2

    The spread of infectious disease between different species of animal and particularly to humans.

Source: https://en.wiktionary.org/wiki/spillover