Topic summary
Grandfather
Extracted from the Wikipedia article Grandparent.
Great-grandparents and beyond
To avoid a proliferation of "greats" when discussing genealogical trees, one may also use ordinals instead of multiple "greats"; thus a "great-great-grandfather" would be the "second great-grandfather", and a "great-great-great-grandfather" would be a third great-grandfather, and so on. One may also use cardinal numbers for numbering greats, for example, great-great-great-grandmother becomes 3×-great-grandmother.