Dictionary
bo'rax pentahy'drate
Chem.
a white, crystalline, water-soluble solid, Na
2B
4O
7·5H
2O, used chiefly for killing weeds, as a water softener, and as a disinfectant and deodorizing agent.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.