The Collaborative International Dictionary
Pentacid
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.
Wiktionary
pentacid
a. (context chemistry English) 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.