The term "peacock" refers only to males of the species. Females are called peahens and their young are peachicks. A group of peafowl is called a "party" or "ostentation."
The showy feathers of the peacock are actually the tail coverts and are sometimes referred to as a "train". These brightly colored plumes number between 100 and 150 and are fanned and shaken to attract the attention of the peahens. The actual tail is beneath these feathers and helps to support their weight.