/ Dictionary / Index P pyrosulfuric acid: Meaning and Definition of Find definitions for: py'rosulfu'ric ac'id Pronunciation: [key] — Chem. Chem. an oily, hygroscopic, corrosive liquid, HSO, that, depending on purity, is colorless or dark brown: used chiefly as a dehydrating agent in the manufacture of explosives and as a sulfating or sulfonating agent in the manufacture of dyes. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrosulfuric pyrotechnic Related Content Daily Word Quiz: abscond Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language