Pronunciation: (pol"ē-as'id), [key] Chem.
1. having more than one replaceable hydrogen atom.
2. capable of reacting with more than one equivalent weight of an acid.
1. an acid having more than one replaceable hydrogen atom.
2. an oxyacid containing the equivalent of extra molecules of its anhydride, as the polysulfuric acids, H2S2O7 or H2SO4·SO3, and H2S3O10 or H2SO4·2SO3.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.