1- Half-great-grandpibling's great-grandchild.
2- Living being that has zero parents, zero grandparents, zero great-grandparents and one great-great-grandparent in common with other living beings.
When inbreeding happened sometime in your recent family history and so now you have overlapping cousins (not 2nd cousins)
"Why my families lived in this county for 120 years. There didn't used to be that many people here, and were full red blooded Americans. Do you know what that means?"
"What?"
"I've got some cousin cousins"
Child of their maternal first cousin with the paternal first cousin or double-first cousin’s child.
My double-first cousin-nibling is a good person.
Daughter of their maternal first cousin’s child with the paternal first cousin’s child or double-first cousin’s granddaughter.
My double-great-cousin-niece is a good person.
Sesqui-first cousin’s grandson.
My sesqui-great-cousin-nephew is a good person.
Fourth-cousin-seven-times-removed (4C7R).
My fourth-cousin-7X-removed is a good person.