Someone who, in relation to others, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and twenty great-great-great-grandparents in common.
Decuple-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and twenty great-great-great-grandparents in common.
My decuple-fourth-cousin is a good person.
Someone who, in relation to others, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and nineteen great-great-great-grandparents in common.
Irregular-decuple-fourth-cousin.