It could be derived from the ancient Castellum Cattorum, a castle of your Chatti, a German tribe that experienced lived in the area because Roman times. A further assumption can be a portmanteau from Frankonian cas, meaning "valley or recess", and sali this means "hall or services setting up", which https://z-gern-sie-nicht53196.hyperionwiki.com/764936/the_5_second_trick_for_dienst