pe·rid·o·tite \pəˈridəˌtīt\noun (-s) Etymology: French péridotite, from péridot + -ite : any of a group of granitoid igneous rocks composed of olivine and usually other ferromagnesian minerals but with little or no feldspar and usually occurring in dikes or small intrusive bodies • pe·rid·o·tit·ic\ ̷ ̷| ̷ ̷ ̷ ̷|tid.ik\adjective