The gender-neutral term for a niece or nephew (by analogy with sibling).
Nephlings are the delightful creatures you can adore and play with and who look up to you, but whose diapers you don't have to change and whose tantrums are not your problem. The warm feeling you get from seeing your nephlings is unconscious gratification that your genes are being passed on (indirectly) to the next generation, without any effort of your own.
How many nephlings do you have? How many of those are nieces? Anyway, my nephlings are cuter than yours.
A neighbor child, especially one with a propensity for getting your own children in trouble. Someone who lives in your house and backyard by day, but goes someplace else at night to dream up more mischief.
No, we only have three children. That's right, the three with shoes on. That other one is a neighborhoodlum.