What is a Cousin-in-Law?

Marc McDermott
February 22, 2022

The more in-depth the search, the more interesting, yet more complex your family tree becomes. When it comes to cousins, many people ask what is a cousin in law? This is a valid question, but a cousin in law is a term used to describe the husband or wife of someone’s cousin

So, if your cousin married, their new partner would be your cousin-in-law. With many questions on the tip of people’s tongues, we’re going to take a closer look so you can better understand the relationship between you and your cousin-in-law when you find them on your family tree, or they enter the family.

Is a cousin-in-law a real thing?

Yes, it is. While there is no legal reason behind the name, your cousin-in-law is a relation on your family tree as this person married your cousin. 

So, legally there is no reason why it should matter, but from a social point of view, it is important to know how you are related to others. Not only this, but you will want to be able to organize your family tree when it comes to adding relatives. 

What do you call a cousin-in-law?

Well, this is a simple one in some ways. You can call them your cousin’s wife or husband, or your cousin-in-law. Cousin in law is a more accurate description from a genealogical point of view, but other people will know exactly how this person is related to you, whichever description you use.

Find out which your cousin-in-law prefers in social situations so you know exactly where you stand unless you are not often in one another’s company, in which it matters less. 

Is a cousin-in-law a blood relation?

No, they are not. Your cousin’s spouse is not related to you in DNA or blood, but their spouse will be like this child will share some of the DNA from your cousin, which will be the same as yours in some percentage. 

Since a cousin-in-law is someone who enters your family by marriage and not blood, they are not considered a blood relation. They are also not a “close relative” in the same way that your siblings, parents, grandparents, or even to a lesser extent, your cousins (including the one they married).

Is your cousin-in-law a relative?

They are in the sense that they make up part of your family tree. If they have a spouse with your cousin, then their children enter your family tree. These children are your first cousins once removed. Also, your cousins’ children would be the second cousins to your children.

Their children are part of the same generation as you but with an additional generation between you and your common ancestor. 

The closeness between you and your cousin-in-law will likely depend on the relationship between you and your cousin. If you see one another often then you may form a friendship with them, and their kids and your kids can grow up knowing one another. At least now you know how they are related.

Either way, a cousin-in-law is yet another person to add to your family tree should the time arise. 

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