andesitePronunciation: /ˈandɪzʌɪt, -sʌɪt/Definition of andesite noun [mass noun] Geology a dark, fine-grained, brown or greyish intermediate volcanic rock which is a common constituent of lavas in some areas. Derivatives andesitic adjective Origin: mid 19th century: named after the Andes mountains, where it is found + -ite1andesite in other Oxford dictionaries Definition of andesite in the US English dictionary
