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.

• 前寒武纪的地质年代中最古老和最大的阶段的、属于这一阶段的或处于这一阶段的，其前为寒武纪期，寒武纪期又可细分为始生代和原生代，特征为原始生命形式的出现