Pronunciation: (mēr'shum, -shôm), [key]
1. a mineral, hydrous magnesium silicate, H4Mg2Si3O10, occurring in white, claylike masses, used for ornamental carvings, for pipe bowls, etc.; sepiolite.
2. a tobacco pipe with a bowl made of this substance.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.