What is "triacid"

Triacid \Tri*ac"id\, a. [Pref. tri- + acid.] (Chem.) Capable of neutralizing three molecules of a monobasic acid or the equivalent; having three hydrogen atoms which may be acid radicals; -- said of certain bases; thus, glycerin is a triacid base.

a. (context chemistry of a base English) Capable of combining with three molecules of a monobasic acid