Dictionary
di'atoma'ceous earth'
a fine siliceous earth composed chiefly of the cell walls of diatoms: used in filtration, as an abrasive, etc.
Also called di•at•o•mitePronunciation: (dī-at'u-mīt"), [key] kieselguhr. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.