Of, belonging to, or being the oldest and largest division of geologic time, preceding the Cambrian Period, often subdivided into the Archeozoic and Proterozoic eras, and characterized by the appearance of primitive forms of life.
英
美
- 前寒武紀的地質(zhì)年代中最古老和最大的階段的、屬于這一階段的或處于這一階段的,其前為寒武紀期,寒武紀期又可細分為始生代和原生代,特征為原始生命形式的出現