The great-grandparent of one's spouse.
My great-grandparent-in-law is a good person.
by Rwopazaq November 24, 2019
Get the great-grandparent-in-lawmug. Great-great-grandchild's son.
My great-great-great-grandson is a good person.
by Mr. Jacov November 23, 2019
Get the great-great-great-grandsonmug. First cousin's great-great-granddaughter.
by Gtopql November 23, 2019
Get the first great-great-great-cousin-niecemug.
Get the step-great-grandparent-in-lawmug.
Get the step-great-granddaughter-in-lawmug. 
