The Answer
Nibling is an, as yet unofficial, gender-neutral word to describe your sibling’s children (nieces and nephews).
Have you ever wondered why there’s a gender-neutral term for your brother or sister (sibling) but not one for your sibling’s child?
In 1951, Samuel E. Martin got tired of saying nieces and nephews and solved the problem by coming up with a brand new word.
Nibling is a gender-neutral term used to refer to a child of one’s sibling as a replacement for “niece” or “nephew”. The word is thought to have been coined in the early 1950s, but was relatively obscure for several decades before being revived in recent years.
Unfortunately, despite its usefulness, the word does not appear in most dictionaries yet. In 2004, a group of English schoolchildren campaigned to have it added to the Oxford English Dictionary. With any luck, the powers that be will honour our nibling-related wishes.