daciteEnglishOxford Dictionary of Englishdacite /ˈdeɪsʌɪt / ▸ noun [mass noun] Geology a volcanic rock resembling andesite but containing free quartz. – DERIVATIVES dacitic /deɪˈsɪtɪk/ adjective– ORIGIN late 18th century: from the name of the Roman province of Dacia(as it was first found in the Carpathian Mountains) + -ite1.