What does "peacock" mean?

Peacock: In common usage, the species in general or collectively; a peafowl. Peacock butterfly (Zoöl.), a handsome European butterfly (Hamadryas Io) having ocelli like those of peacock. -- Peacock fish (Zoöl.), the European blue-striped wrasse (Labrus variegatus); -- so called on account of its brilliant colors. Called also cook wrasse and cook. -- Peacock pheasant (Zoöl.), any one of several species of handsome Asiatic pheasants of the genus Polyplectron. They resemble the peacock in color.