A friend has a hypernym for niece-or-nephew: "nibling".    From Wordnik.com.  [On needed words] Reference

Actually it looks like you can use perpetuate in that context, meaning to uphold, the hypernym of perpetuate.    From Wordnik.com.  [Educating America: Cheating on papers is a booming Web business] Reference

Fäustling, its hypernym glove is Handschuh.    From Wordnik.com.  [Strange Maps] Reference