Proterozoic

adjective Pro·te·ro·zo·ic \ ˌprä-tə-rə-ˈzō-ik , ˌprō- \

Definition of Proterozoic

: of, relating to, or being the eon of geologic time or the corresponding segment of rocks that includes the interval between the Archean and Phanerozoic eons, exceeds in length all of subsequent geologic time, and is marked by rocks that contain fossils indicating the first appearance of eukaryotic organisms (such as algae) — see Geologic Time Table

Proterozoic

noun

Origin and Etymology of proterozoic

Greek proteros former, earlier (from pro before) + International Scientific Vocabulary -zoic — more at for


Learn More about proterozoic


Seen and Heard

What made you want to look up Proterozoic? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

an inference not connected logically

Get Word of the Day daily email!

Test Your Vocabulary

Find the Cousins

  • a-large-tree-with-many-branches
  • Which pair shares a common word ancestor?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!