silicatePronunciation: /ˈsɪlɪkeɪt, -kət/Definition of silicate noun Chemistry a salt in which the anion contains both silicon and oxygen, especially one of the anion SiO42−. any of the many minerals consisting of silica combined with metal oxides, forming a major component of the rocks of the earth’s crust. silicate in other Oxford dictionaries Definition of silicate in the US English dictionary