- the anion OH−.
Origin of hydroxide ion
First recorded in 1950–55
Also called hydroxyl ion.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for hydroxide ion
That is, different concentrations of hydrogen-ion or of hydroxide-ion are required to change their colors.
The second table gives, similarly, the concentrations of hydroxide-ion required to produce the changes of tint indicated.
This is an indicator for bases and acids, like litmus, but it is less sensitive to hydroxide-ion than is litmus.