WordReference Random House Unabridged Dictionary of American English © 2026
phos′phorus pent•ox′ide
(pen tok′sīd, -sid),USA pronunciation [Chem.]
- Chemistrya white, deliquescent, crystalline powder, P2O5, that, depending upon the amount of water it absorbs, forms orthophosphoric acid, metaphosphoric acid, or pyrophosphoric acid, produced by the burning of phosphorus in dry air: used in the preparation of phosphoric acids, as a drying and dehydrating agent, and in organic synthesis. Also called phosphoric anhydride.
'phosphorus pentoxide' also found in these entries (note: many are not synonyms or translations):