1- Half-great-great-grandpibling's great-great-grandchild.
2- Someone who, in relation to others, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and one great-great-great-grandparent in common.
Half-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and one great-great-great-grandparent in common.
My half-fourth-cousin is a good person.