Definition:Separable Extension

Definition
Let $K$ be a field.

Let $L/K$ be a field extension of $K$.

Then $L/K$ is a separable extension every $\alpha\in L$ is separable over $K$.

That is:
 * For every $\alpha \in L$, its minimal polynomial over $K$ is separable.

Also see

 * Definition:Normal Extension
 * Definition:Galois Extension