The Collaborative International Dictionary
Polybasic
Polybasic \Pol`y*ba"sic\, a. [Poly- + basic.] (Chem.) Capable of neutralizing, or of combining with, several molecules of a monacid base; having several hydrogen atoms capable of being replaced by basic radicals; -- said of certain acids; as, sulphuric acid is polybasic.
Wiktionary
polybasic
a. 1 (context chemistry of an acid English) containing two or more replaceable hydrogen atoms 2 (context chemistry of a salt English) having two or more atoms of a univalent metal 3 (context chemistry of a base English) Having two or more basic groups; see also polybase