Diatom
['daɪətəm]
Definition
(noun.) microscopic unicellular marine or freshwater colonial alga having cell walls impregnated with silica.
Typed by Agatha--From WordNet
Definition
(n.) One of the Diatomaceae, a family of minute unicellular Algae having a siliceous covering of great delicacy, each individual multiplying by spontaneous division. By some authors diatoms are called Bacillariae, but this word is not in general use.
(n.) A particle or atom endowed with the vital principle.
Edited by Griffith