A person away from his or her usual environment or activities. For example, Using a computer for the first time, Carl felt like a fish out of water, or On a hiking trail, Nell was a fish out of water. This expression alludes to the fact that fish cannot survive for long on dry land. [Late 1300s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.