white rat 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.
an albino rat, esp. one used in biological experiments
white rat 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.
A domesticated albino variety of the Norway rat.
white rat - Medical Definition
A domesticated albino variety of the Norway rat, used extensively in laboratory experiments.