1. The grandchild-in-law of one's sibling.
2. The grandchild of one's spouse's sibling.
My grandnibling-in-law is a good person.
by Elivaldeq November 24, 2019
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I have 212 great-great-grandniblings (106 great-great-grandnieces and 106 great-great-grandnephews).
by Gerald128 April 6, 2021
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