Child of their maternal first cousin’s child with the paternal first cousin’s child or double-first cousin’s grandchild.
My double-first great-cousin-nibling is a good person.
Seventh-cousin-six-times-removed (7C6R).
My seventh-cousin-6X-removed is a good person.
Someone who, in relation to others, has zero parents, zero grandparents and three great-grandparents in common.
Irregular-double-second-cousin.
Living being that has zero parents, zero grandparents and three great-grandparents in common with other living beings.
irregular-double-second-cousin
1. The husband of one's grandparent's sibling's daughter.
2. The son of one's grandparent-in-law's sibling.
My first cousin-uncle-in-law is a good person.