If someone walked up to you and said "Howdy, I'm your third cousin, twice removed," would you have any idea what they meant?

Most people have a good understanding of basic relationship words such as "mother," "father," "aunt," "uncle," "brother," and "sister." But what about the relationship terms that we don't use in everyday speech?

Terms like "second cousin" and "first cousin, once removed"? We don't tend to speak about our relationships in such exact terms ("cousin" seems good enough when you are introducing one person to another), so most of us aren't familiar with what these words mean.

Relationship Terms

Sometimes, especially when working on your family history, it's handy to know how to describe your family relationships more exactly. The definitions below should help you out.

Cousin (a.k.a "first cousin")

Your first cousins are the people in your family who have two of the same grandparents as you. In other words, they are the children of your aunts and uncles.

Second Cousin

Your second cousins are the people in your family who have the same great-grandparents as you., but not the same grandparents.

Third, Fourth, and Fifth Cousins

Your third cousins have the same great-great-grandparents, fourth cousins have the same great-great-great-grandparents, and so on.

Removed

When the word "removed" is used to describe a relationship, it indicates that the two people are from different generations. You and your first cousins are in the same generation (two generations younger than your grandparents), so the word "removed" is not used to describe your relationship.

The words "once removed" mean 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.

Since genealogy does not have a "third removed," if you are three generations removed from the common ancestor, you become a second cousin to the original first cousin. Your children then become second cousins, once removed and their children become second cousins, twice removed.

To simplify this, here's an example from my family. I have a dear friend whose mother is a first cousin to my father because her mother and my father shared a set of common grandparents.

That makes her my father's first cousin, once removed, and it makes me her mother's first cousin, once removed, since we are both great grandchildren of our parents' shared grandparents (We are "one" generation further removed than her mother and my father from that common ancestor). Conversely, it makes the two of us first cousins, twice removed.

My children, who are great-great grandchildren of that same common ancestor, become her mother's second cousin, and her children are my father's second cousins. That makes our children second cousins, once removed to us.

It then makes our children second cousins, twice removed to one another.

Our grandchildren finally become third cousins of my father and her mother. They are conversely third cousins, once removed to her and me while they become third persons, twice removed to one another.

So, let's go back to opening question. One's third cousin, twice removed, would mean that the two of you are both great-great-great-grandchildren of a shared set of grandparents.

Got that???It should be as clear as mud by now. A simple way to keep it straight is to prepare a chart, listing the familial relationship to a common ancestor of one of your first cousins and figure out the relationship of each succeeding generation back to the first cousins.