/mear"sheuhm, -shawm/ , n.
1. a mineral, hydrous magnesium silicate, H 4 Mg 2 Si 3 O 10 , 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.
[ 1775-85; Meerschaum, equiv. to Meer sea (see MERE 2 ) + Schaum foam ]