si·meth·i·cone 
(sĭ-mĕthĭ-kōn′)
(sĭ-mĕthĭ-kōn′)n.
A mixture of methyl siloxane polymers and silica gel, used an antiflatulent drug and as an antifoaming agent in cosmetics and industrial applications.
[SI(LICA) + (di)methicone, a silicon polymer (DI- + METH- + (SIL)ICONE).]