capable of combining with two molecules of a monobasic acid.
(of an acid or a salt) having two replaceable hydrogen atoms.
Origin of diacid
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
an acid or salt that contains two acidic hydrogen atoms
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