Definition of Proterozoic in English:



  • 1Relating to or denoting the eon that constitutes the later part of the Precambrian, between the Archean eon and the Cambrian period, in which the earliest forms of life evolved.

    • ‘The key to understanding the early evolution of eukaryotes lies in the Proterozoic fossil record, especially microfossils.’
    • ‘No rock standard has been identified formally as marking the base; at the top of the Proterozoic the Cambrian - Precambrian boundary is identified on the basis of fossils.’
    • ‘This is the general name for all Archaean and Proterozoic basement gneisses of the NW Scotland mainland and Outer Hebrides.’
    • ‘The bulk of the Mozambique belt of eastern Africa and Madacascar is underlain by deeply eroded and multiply deformed high-grade Proterozoic and Archaean rocks.’
    • ‘Archean and most Proterozoic sedimentary rocks are notable for their distinct lack of any bioturbated textures.’
    1. 1.1as noun the Proterozoic The Proterozoic eon or the system of rocks deposited during it.


Late 19th century: from Greek proteros ‘former’ + zōē ‘life’, zōos ‘living’ + -ic.