Non-gender specific form of neice or nephew. As 'sibling' is to brother and sister. And 'spouse' is to husband and wife - 'Neibling' is to neice or nephew.
"My latest neibling was born today. Welcome to the world Darcy."
" How many neiblings have you got?"
" How many neiblings have you got?"
by patbk November 29, 2013