nibling       
noun [ C ] uk/ˈnɪb.lɪŋ/ us/ˈnɪb.lɪŋ/
 侄子;外甥;侄女;外甥女
a child of your sibling (= brother or sister)
  It's a photo of my parents holding my newest nibling. 这张照片是我父母抱着我最小的甥侄辈孩子。 
 I want to send some gifts to my niblings. 我想给我的甥侄辈孩子们送点礼物。 
 Compare: niecenephew
 - More examples
 - My sister just had her first scan. Hello my future nibling!
 - I took my niblings trick or treating.
 - My nibling just told me pterodactyls are related to dinosaurs but not actual dinosaurs.