Dictionary
py'rosulfu'ric ac'id
Chem.
an oily, hygroscopic, corrosive liquid, H
2S
2O
7, 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
fuming sulfuric acid, oleum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.