/flooh"oh si lis"ik, flooh'-/ , Chem.
an unstable acid, H 2 SiF 6 , known only in its colorless, poisonous, fuming aqueous solution or in the form of its salts: used chiefly as a wood preservative, a disinfectant, and as a hardening agent in the manufacture of ceramic ware, cement, and concrete.
[ FLUO- + SILICIC ]