In historical sources, the castle can be found mentioned under two names. In the oldest mentions, it is called by the name of its founder Detrich – Detrich’s Rock. This denomination survived until today in the Hungarian name of the castle (Detrekö vár). The origin of the original Slovak name is entirely different; historians see it in the name of the Cuman tribe, originating from the steppe of eastern Russia. Cumans fled from the approaching Tatars to Hungary, where the then ruler Belo IV. hired them as the guards of the western border.
Allegedly, the local people called the foreign warriors „Plavci“ (pales) due to their bright hair color and so the castle Detrich’s Rock became Plavecký castle in the Slovak language, as a remembrance of the foreign guards of the frontier. The adjective derived from the name of the castle (Plavecký) came to be used in the names of the surrounding villages belonging to the castle estate.