Ties to the unfortunate Mama are now unraveling, leaving Cass or Cassie to stand on its own as a fresher sounding Cathy or Kate. But with so many lovely long forms, we'd advise keeping this as a nickname.

A light variation of any of the weightier names beginning with Cas, such as Casper, Cassius etc- this is a beautifully mellow and soft name that bears greater consideration.