half-third-cousin 

Half-3C:
1- Parent's half-second-cousin's child.
2- Grandparent's half-first-cousin's grandchild.
3- Great-grandparent's half-sibling's great-grandchild.
4- Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents and one great-great-grandparent in common.

My half-third-cousin is a good person.

half-third-cousin by Gerald128 May 17, 2021

sester-fourth-cousin

Sester-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and five great-great-great-grandparents in common.

My sester-fourth-cousin is a good person.

sester-fourth-cousin by ABGR June 9, 2021

4.5-tuple-fourth-cousin 

4.5-tuple-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and nine great-great-great-grandparents in common.

My 4.5-tuple-fourth-cousin is a good person.

4.5-tuple-fourth-cousin by ABGR June 9, 2021

sextuple-fourth-cousin 

Sextuple-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and twelve great-great-great-grandparents in common.

My sextuple-fourth-cousin is a good person.

sextuple-fourth-cousin by ABGR June 9, 2021

10.5-tuple-fourth-cousin 

10.5-tuple-4C: Person who, in relation to the other person, has zero parents, zero grandparents, zero great-grandparents, zero great-great-grandparents and twenty-one great-great-great-grandparents in common.

My 10.5-tuple-fourth-cousin is a good person.

10.5-tuple-fourth-cousin by ABGR June 9, 2021

step-first-cousin 

1- Pibling's stepchild.
2- Steppibling's child.
3- Stepcousin.

My step-first-cousin is a good person.

step-first-cousin by User655 July 25, 2021

co-third-cousin-in-law

Spouse's third-cousin's spouse.

My co-third-cousin-in-law is a good person.

co-third-cousin-in-law by JAMP12 September 21, 2021