'Pentacid' definitions:

Definition of 'Pentacid'

From: GCIDE

Pentacid \Pen*tac"id\, a. [Penta- + acid.] (Chem.) Capable of neutralizing, or combining with, five molecules of a monobasic acid; having five hydrogen atoms capable of substitution by acid residues; -- said of certain complex bases. [1913 Webster]