ar·cheo·zo·ic I. adjective alsoar·chaeo·zo·ic\|ärkēə|zōik sometimes är|k-\ Usage: usually capitalized Etymology:archae- + -zoic : of, belonging to, or relating to the earliest era of geological history, the era of the Archean rocks — see geologic time table II. noun alsoarchaeozoic\“\ (-s) Usage: usually capitalized : the Archeozoic era or system of rocks