In this month’s Genealogy Corner, we explain the often-confusing terms and definitions related to cousins, including one and twice removed.

First Cousin
Your first cousin is a child of your aunt or uncle. You share one set of grandparents with your first cousin, but do not have the same parents.

Second Cousin
Your second cousin is the grandchild of your great-aunt or great-uncle. You share one set of great-grandparents with your second cousin, but do not have the same grandparents.  

Third, Fourth and Fifth Cousin
Your third cousin is the great-grandchild of your great-great-aunt or great-great-uncle. You share a set of great-great grandparents with your third cousin, but do not have the same great-grandparents. Fourth cousins have one set of great-great-great grandparents, but not the same great-great-grandparents, and so on.

Double Cousins
If two siblings in one family marry two siblings from another family and each couple has a child, the children are double first cousins. The world “double” means they share the same four grandparents. Regular first cousins share only one set of common grandparents, while double first cousins share both sets of grandparents plus all lineal and collateral relatives.

Removed
When the word “removed” is used to describe a relationship, it indicates that the two people are from different generations. “Once removed” means that there is a difference of one generation. For example, your mother’s first cousin is your first cousin, once removed. This is because your mother’s first cousin is one generation younger than your grandparents and you are two generations younger than your grandparents. This one-generation difference equals “once removed.”

Twice removed means that there is a two-generation difference. You are two generations younger than a first cousin of your grandmother, so you and your grandmother’s first cousin are first cousins, twice removed.

Below is a helpful chart about cousins “removed.”

Common Ancestor	Child	Grandchild	G-grandchild	G-g-grandchild
Child	Sister or Brother	Nephew or Niece	Grand-nephew or niece	G-grand-nephew or niece
Grandchild	Nephew or Niece	First cousin	First cousin, once removed	First cousin, twice removed
G-grandchild	Grand-nephew or niece	First cousin, once removed	Second cousin	Second cousin, once removed
G-g-grandchild	G-grand-nephew or niece	First cousin, twice removed	Second cousin, once removed	Third cousin