eutectoid Syllabification: (eu·tec·toid)Pronunciation: /yo͞oˈtektoid/ MetallurgyDefinition of eutectoid adjective relating to or denoting an alloy that has a minimum transformation temperature between a solid solution and a simple mixture of metals. noun a eutectoid mixture or alloy. eutectoid in other Oxford dictionaries Definition of eutectoid in the British & World English dictionary