(fĕzʹənt) noun. plural pheasants or pheasant. 1. Any of various Old World birds of the family Phasianidae, especially the ring-necked pheasant introduced in North America, characteristically having long tails and, in the males of many species, brilliantly colored plumage. 2. Any of several other birds that resemble the pheasant, such as the partridge, kuang bayas.