1. Of or relating to a period of time intervening between (periods designated as) ancient and modern: In Marburg, Germany, there is a medieval castle that is worthwhile visiting!

In history, the medieval times were in the Middle Ages. There were medieval scholars, art, and religion at the time of te Middle Ages.
2. Descriptive of something as if it belonged to the Middle Ages; old-fashioned; obsolete: Sharon's parents certainly had a medieval attitude towards her dating a boy because they always wanted to go along with them!