There are two definitions.
1.) The 4th released song by American pop music artist Lady GaGa.
2.) Term used in America for people with cameras that basically stalk a celebrity and take pictures of them. Italian for " annoying bug".
1.) "I'm your biggest fan I'll follow you until you love me, papa paparazzi!" - Paparazzi, Lady GaGa
2.) I can't believe when Tiger Woods left the grocery store there was no paparazzi to take pictures of him!