adj, name ·Rare ·Advanced level

Definitions

Adjective

1. 1
   Of a geologic era within the Proterozoic eon from 2,500 to 1,600 million years ago. not-comparable

Proper Noun

1. 1
   The era from 2,500 Ma to 1,600 Ma, marked by a dramatic increase in atmospheric oxygen.

Synonyms

All synonyms

mesoproterozoic

Etymology

From paleo- + Proterozoic.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.