bone ashbone ash
a white porous ash prepared by burning bones in the open air and consisting chiefly of calcium phosphate: used in making bone china and in fertilizers
also bone earth
The white, powdery calcium phosphate ash of burned bones, used as a fertilizer, in making ceramics, and in cleaning and polishing compounds.
(plural bone ashes)
- The white, powdery ash left when bone is burnt; it is high in calcium phosphate and is used as a fertilizer and in making bone china.