/ Dictionary / Index P perchloric acid: Meaning and Definition of Find definitions for: perchlo'ric ac'id Pronunciation: [key] — Chem. Chem. a colorless, syrupy hygroscopic liquid, HClO, an acid of chlorine containing one more oxygen atom than chloric acid: used chiefly as a reagent in analytical chemistry. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. perchloric perchloride Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language