geologic time definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the time period (c. 4.55 billion years) representing the earth's geologic history
geologic time definition by American Heritage Dictionary
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The period of time covering the physical formation and development of Earth, especially the period prior to human history.
geologic time - Science Definition
The period of time covering the formation and development of the Earth, from about 4.6 billion years ago to today.