Your sister or brother's child, who exists as one of the 11 recognized genders, but you can't really be bothered to think too much about it, so yeah; baby cousin.
Yeah, you know Ronnie's friend AJ? Her man's...... Baby cousin
First cousin's great-great-grandson.
My great-great-great-cousin-nibling is a good person.
7.5-tuple-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and fifteen great-great-great-grandparents in common.
My 7.5-tuple-fourth-cousin is a good person.
Daughter of their grandparent’s full sibling with the other grandparent’s full sibling.
My double-cousin-aunt is a good person.
Someone who, in relation to others, has zero parents, zero grandparents, zero great-grandparents and six great-great-grandparents in common.
Triple-3C:
Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents and six great-great-grandparents in common.
My triple-third-cousin is a good person.
Living being that has zero parents, zero grandparents, zero great-grandparents and six great-great-grandparents in common with other living beings.