Source : Webster's Revised Unabridged Dictionary (1913)

Kieselguhr \Kie"sel*guhr`\, n. [G., fr. kiesel flint + guhr an
   earthy deposit or sediment in water.]
   Siliceous earth; specifically, porous infusorial earth, used
   as an absorbent of nitroglycerin in the manufacture of
   dynamite.

Source : WordNet®

kieselguhr
     n : a light soil consisting of siliceous diatom remains and
         often used as a filtering material [syn: {diatomaceous
         earth}, {diatomite}]