Eutectoid /juːˈtɛktɔɪd/ (eutectic and Greek. eidos-xyl) – similar structural constituent of metal alloys in eutectic; but unlike eutectic, it is formed in solid phase and not in liquid phase. Therefore, two or more phases have a finely dispersed internal structure. Pearlite (steel with a certain structure) is an example of a eutectoid.
Ex.On further cooling to eutectoid temperature, the austenite will transform to pearlite.