1) Chemical nomenclature 
• (a.) Capable of neutralizing three molecules of a monacid base, or their equivalent; having three hydrogen atoms capable of replacement by basic elements on radicals; -- said of certain acids; thus, citric acid is a tribasic acid.
Type: Term Pronunciation: trī-bā′sik Definitions: 1. Having three titratable hydrogen atoms; denoting an acid with a basicity of 3.