A third cousin is a relative who shares the same great-great-grandparents with you. This means that both you and your third cousin are descended four generations down from those common ancestors. Specifically, your third cousin is the child of your parent's second cousin. To put it simply, your grandparents and your third cousin's grandparents are first cousins, your parents and their parents are second cousins, and you and your third cousin are third cousins
. In terms of family tree structure:
- You and your third cousin share great-great-grandparents.
- Your grandparents and your third cousin's grandparents are first cousins.
- Your parents and your third cousin's parents are second cousins.
- You and your third cousin are third cousins.
Third cousins are part of your extended family but are more distantly related than first or second cousins. They share a smaller amount of DNA on average, and the relationship may not be as close socially or genetically
. Additionally, the term "once removed" can apply if there is a generational difference, such as the child of your third cousin being your third cousin once removed
. In summary, a third cousin is someone who shares your great-great- grandparents, making them a distant but traceable relative in your extended family lineage.
