ordinary water, as opposed to heavy water; water containing the normal proportion of deuterium oxide.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for light water
Historical Examples of light water
It is somewhere, then, between her light-water load-line and her bilge.The Sea Lions
James Fenimore Cooper
a name for water (H 2 O), as distinct from heavy water
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
Ordinary water, H2O. Compare heavy water.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.