Temporalities are the secular properties and possessions of the Christian Church. It is most often used to describe those properties (a Stift or sticht in German or Dutch language) that were used to support a bishop or other religious person or establishment. Its opposite description would be the spiritualities.
In the Middle Ages, the temporalities were usually those lands that were held by a bishop, that were used to support him. After the Investiture Crisis was resolved, the temporalities of a diocese were usually granted to the bishop by the secular ruler after the bishop was consecrated. If within the Holy Roman Empire a bishop had gained secular overlordship to his temporalities imperially recognised as an imperial state then the temporalities were usually called Hochstift, or Erzstift (for an archbishop). Sometimes this granting of the temporalities could take some time. Sometimes a bishop elect gained his temporalities even before or without his papal confirmation by an imperial act called liege indult (Lehnsindult). The temporalities were often confiscated by secular rulers to punish bishops.