follow Dictionary.com

11 Trending Words of 2014

Proterozoic

[prot-er-uh-zoh-ik, proh-ter-] /ˌprɒt ər əˈzoʊ ɪk, ˌproʊ tər-/
adjective
1.
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.
noun
2.
the Proterozoic division of geologic time or the rock systems formed then; Algonkian.
Origin
1905-1910
1905-10; protero- + zo- + -ic
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for Proterozoic
  • The first organisms having features typical of fungi date to , the Proterozoic.
British Dictionary definitions for Proterozoic

Proterozoic

/ˌprəʊtərəʊˈzəʊɪk/
noun
1.
the later of two divisions of the Precambrian era, during which the earliest plants and animals are assumed to have lived Compare Archaeozoic
adjective
2.
of or formed in the late Precambrian era
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for Proterozoic
adj.

1880, from protero- + zoic.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
Proterozoic in Science
Proterozoic
  (prŏt'ər-ə-zō'ĭk)   
The later of the two divisions of the Precambrian Eon, from about 2.5 billion to 540 million years ago. The Proterozoic was characterized by the formation of stable continents, the appearance of abundant bacteria and archaea, and the buildup of oxygen in the atmosphere. By about 1.8 billion years ago the oxygen buildup was significant enough to cause many types of bacteria to die out. At this time eukaryotes, including multicellular algae and the first animals, first appear in the fossil record. See Chart at geologic time.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source

Word of the Day

Difficulty index for Proterozoic

Few English speakers likely know this word

Word Value for Proterozoic

0
0
Scrabble Words With Friends