Proterozoic: Meaning and Definition of
Pronunciation: (prot"ur-u-zō'ik, prō"tur-), [key]
— Geol. Geol.
- noting or pertaining to the latter half of the Precambrian Era, from about 2.5 billion to 570 million years ago, characterized by the appearance of bacteria and marine algae; Algonkian.
- the Proterozoic division of geologic time or the rock systems formed then; Algonkian. See table under
- proterozoic (Thesaurus)