1. containing in each molecule two atoms of hydrogen replaceable by basic atoms or radicalsusually said of acids and acid salts
2. capable of forming a salt or ester by reacting with one molecule of a diacid, or two of a monoacidusually said of bases and alcohols
3. an acid having in each molecule two hydrogen atoms which can be replaced by a metal or react with basic substances
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.