peacock, any of three species of resplendent birds of the pheasant family, Phasianidae (order Galliformes).Strictly, the male is a peacock, and the female is a peahen; both are peafowl. The two most-recognizable species of peafowl are the blue, or Indian, peacock (Pavo cristatus), of India and Sri Lanka, and the green, or Javanese, peacock (P. muticus), found from Myanmar (Burma) to Java.