What is 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 called?

triacid — 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. (Webster's 1913.)

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