What Do You Call Your Moms Cousin?

Here is what genealogy.com has to say on the matter

Figuring Out Family Relationships
At Genealogy.com, we get asked about how to determine relationships all the time. Here, you'll learn how to figure out the relationships between family members using a simple chart.

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.

There is also a relationship chart that didn't copy over so well, so if you want to use it go to their site

Your mother's cousin is your 1st cousin once removed. The children of your mother's cousin would be your 2nd cousins.

Second cousins and 2nd cousins have the same great grandfather.

I think your mom's cousin is your first cousin once removed. We always called them second cousins too but my uncle set me straight...he is into family genealogy so he would know.

I would refer to them as my mother's cousin or explain the relationship as both great-grandchildren from old what'sername.

It's your first cousin once removed or just say your mother's cousin to simplify it. And we address them as Uncle or Aunt out of respect in our family. Mr and Mrs were for mom's friends (not relatives).

Ummm, I'm wondering this too. I call my mums  FIRST cousin my aunty because thats what I think they are, whereas my mums, cousin's children will be my second cousin. So basically...

My mums first cousin, is my aunty and her children will be my second cousin :)

please comment as say if I'm right or like wrong!

Your mom's first cousin would be your second cousin.

You mom cousin and your cousins kid is the same thing y'all stupid :P

Your mom cousin would be your 2nd cousin. We always refer our mom cousin as our aunt, being that they was much older.

Your second cousin, duh

Why the heck does everyone think that their called second cousins??? It makes no sense. Your cousins kid is a second cousin, its not that hard to figure out and put that together.