1. Describing the chemical composition or temperature of a mixture of substances that gives the lowest temperature at which the mixture becomes fully molten. A further requirement is that that temperature is lower than the melting point of any of the pure component substances.
2. (chemistry) Describing the thermodynamic equilibrium conditions where a liquid coexists with two solid phases.
- For a mixture with two components at a fixed pressure, the eutectic reaction can only happen at a fixed chemical composition and temperature, called the eutectic point.