[ hahrd-nis ]
/ ˈhɑrd nɪs /


Origin of hardness

before 900; Middle English hardnes,Old English heardnes.See hard, -ness
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for hardness

British Dictionary definitions for hardness

/ (ˈhɑːdnɪs) /


the quality or condition of being hard
one of several measures of resistance to indentation, deformation, or abrasionSee Mohs scale, Brinell hardness number
the quality of water that causes it to impair the lathering of soap: caused by the presence of certain calcium salts. Temporary hardness can be removed by boiling whereas permanent hardness cannot
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

Scientific definitions for hardness

[ härdnĭs ]

A measure of how easily a mineral can be scratched. Hardness is measured on the Mohs scale.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.