| a fine siliceous earth composed chiefly of the cell walls of diatoms: used in filtration, as an abrasive, etc. |
di·at·o·mite  (dī-āt'ə-mīt')  n. A fine, powdered diatomaceous earth used in industry as a filler, a filtering agent, an absorbent, a clarifier, and an insulator. Also called kieselguhr. |
diatomaceous earth di·a·to·ma·ceous earth (dī'ə-tə-mā'shəs, dī-āt'ə-)
n.
A powder made of the desiccated shells of diatoms, used as a filtering agent, adsorbent, and abrasive in many chemical operations.
əˌmaɪt