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What is a Great Uncle or a Great Aunt?

What is a Great-Uncle or a Great-Aunt? In this post, learn who these relatives are to you, and much more.

You will learn:

  • What is a great uncle or great aunt
  • The definition of a half great-uncle or aunt
  • What to call your great-uncle or great-aunt

Many people have known at least one great-uncle or great-aunt. These relatives can be very special to us, since they are a couple generations close to our ancestors than we are.

Even though we are not directly descended from our great aunts and uncles, they are not distant family. Their children are our first cousins once-removed, and their grandchildren are our second cousins.

This is why it is crucial to understand more about these important family members.

What is the definition of a great-uncle or a great-aunt?

The definition of a great-aunt or great-uncle is someone who is a sibling of one of our grandparents. The most recent common ancestor (MRCA) that we share with our great-aunts and uncles is our great-grandparents.

In other words, the meaning of great-aunt or great-uncle is a child of our grandparents from whom we are not descended. We are descended from our grandparents, not their siblings.

How are the grandchildren of your siblings related to you?

You are the great-aunt or great-uncle to the grandchildren of your full and half-siblings. The most recent common ancestor is your parents, since you are most closely descended from them.

Your parents are the great-grandparents of your great-nieces and nephews.

How are your grandparent’s siblings related?

As you now know, the siblings of your grandparents are your great-aunts and great-uncles. You might have any number of great-aunts and uncles in your family tree.

Our great-uncles and great-aunts are close relatives with whom we share substantial percentages of DNA.

I know that in my own family, I have greatly appreciated having a relationship with my great-uncles. They remind me of my grandparents, and are a wonderful source of information about the family tree.

What is a half-great uncle or aunt?

If your grandparent had a half-sibling, then their sibling is your half-great uncle or half-great aunt. The common ancestor that you share is the parent that your grandparent and their sibling share.

For example, if your great-grandparents married and had your grandparent, and then your great-grandparents divorced, and your great-grandmother remarried and had the sibling of your grandparent, then your great-great grandmother is the common ancestor shared between you and your half-great uncle.

That’s quite a sentence!

If their half-sibling was a female, then they are your half-great aunt. Alternatively, if they were male, they are your half-great uncle.

Is it great uncle or grand uncle?

There is a debate raging between genealogists and family tree researchers about whether the siblings of our grandparents should be referred to as our great-aunts and great-uncles or our grand-aunts and grand-uncles.

Some people might even call these relatives, if they are female, “great aunties“. Or should it be “grand aunties”?

Which is correct?

Okay, so it’s not really a “raging” debate, since us genealogist-types tend to be a calm bunch. However, some people do prefer one term over the other.

Some people say that it is better to call our grandparents siblings grandaunts and granduncles. This is because we use “grand” before grandparent, and so it would make sense to call their siblings granduncles.

The reasoning behind the preference is that it might, in theory, help people avoid becoming confused. As we move back in the generations, we do use “great” before our more distant ancestors, like great-grandparents.

Therefore, some people say it is easier to wait until we get to the generation of our great-grandparents before starting to call their siblings great-grand aunts and great-grand uncles.

Many, many people prefer to say great-uncle or great-aunt. For some, it’s easier to say a number of greats than having to remember that you have to start with grand and then add greats.

Even though some genealogists might prefer to say grandaunt over great-aunt, both terms have been in use in the English language for hundreds of years. In fact, there is some evidence that the use of great-uncle or great-aunt precedes granduncle or granduncle by at least 58 years.

It’s popular to say great-uncle and great-aunt, and I doubt that, even if many people write articles about it (such as this one) that people will stop saying it, as they have been saying it for almost 500 years. The most important thing is to understand how they are related.

What you decide to call them is up to you. And your great-uncle or grand-uncle, of course.

Is there such thing as a great-great aunt or great-great uncle?

Yes, we will find many great-great aunts and great-great uncles in our family tree. They are also sometimes referred to as great-granduncles or great-grandaunts.

You might even find them called 2nd great-aunts or 2nd great-uncles. But, what are they, and how are they related to us?

Great grand uncle definition

A great-grand uncle or aunt is a sibling of any of our great-grandparents. Our great-granduncles, or great-great uncles, are children of our great-great grandparents from whom we are not descended.

Those who are descended from our great-granduncles and great-grandaunts (or our great-great aunts and great-great uncles – take your pick) are also related to us on collateral lines of our family tree. Their descendants are related to us as follows:

Most people don’t get the opportunity to know many of the descendants of their great-great aunts and uncles. In fact, if you got the opportunity to know one of your great-grandparents or their siblings, you can consider yourself very lucky.


I hope that you have learned everything that you wanted to know about great-aunts and great-uncles in this post, including how they and their descendants are related to you.

If you have any questions about something that you read in this post, or have a question about how the sibling of an ancestor is related, please join in the discussion below.

Thanks for reading today!

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Friday 3rd of December 2021

This is nothing to do with great (or grand) uncles and aunts - but since English is my third language, I've been trying to wrap my brain around all the greats, and the first/second/thrice removed cousins etc. I'm just going to ask my question anyway: Let's say I have an aunt (my father's sister) who has kids. Am I correct in saying that her kids are still my first cousins? Just like my uncle's (dad's brother) kids?


Tuesday 3rd of May 2022

@Max, Yes, you are correct. First cousins share a common grandparent. Second cousins share a common great-grandparent. Children of your first cousins are first cousins once removed to your (1C1R). Children of your second cousins are 2C1R. Grandchildren of your first cousins are 1C2R to you. Cousins are within the same generations. If you have uneven generations between two people, they are removed -- one, two, or more times.


Sunday 4th of April 2021

I use father-grandfather-greatgrandfather (ggf), 2nd ggf, 3rd ggf, etc. I do the same for mother, aunt, and uncle. I try to enjoy a life of consistency based on science and (what to me is:) ethical behavior.

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