Definition of "phosphite" [phos•phite]

• A salt or ester of phosphorous acid. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Uncle Tom's Rose Tonic contains potassium phosphite and has good fungicidal properties, while SB Plant Invigorator is a foliar feed with fungicidal and pesticidal properties."
• "Phosphate-containing sand was fused and turned into phosphite."
• "This otherwise unknown natural phosphite explains the existence of phosphite-eating bacteria."