Proterozoic has 5 different meanings across 3 categories:
Noun · Adjective · Proper Noun
from 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms
Of or relating to the geologic eon from 2,500 Ma to 541.0±1.0 Ma.
Alternative form of Proterozoic
The eon from 2,500 Ma to 541.0±1.0 Ma, the beginning of the Phanerozoic, marked by the build up of oxygen in the atmosphere and the emergence of primitive multicellular life.