[ar.cha.ism] n [NL archaismus, fr. Gk archaismos, fr. archaios] (1643) 1: the use of archaic diction or style
2: an instance of archaic usage
3: something archaic; esp: something (as a practice or custom) that is outmoded or old-fashioned -- ar.cha.ist n -- ar.cha.is.tic adj -- ar.cha.ize vb