Your first cousin's child is your first cousin once removed. Since the child of your cousin is a generation away from you they are the once removed.
So, your second cousin's child is your second cousin, once removed, and so forth.
; First Cousin Once removed. Explaination from http://www.genealogy.com/16_cousn.html.
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; 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.
Your child and your first cousin's child are second cousins to each other.
Your child and your second cousin's child are third cousins to each other.
Your child and your third cousin's child are fourth cousins to each other.
Your first cousin's child is your first cousin once removed.
Your second cousin's child is your second cousin once removed.
Etc.
What do u mean by once removed?
great cousin
First cousin once removed.
Your child and your niece are first cousins to each other. Your child and your niece's child are first cousins, once removed.
Your child and your nephew are first cousins. Your child and your great nephew are first cousins, once removed.
Your uncle's granddaughter and your child are second cousins.
First cousin once removed.
You and the child of your second cousin are second cousins, once removed.
Your first cousin's child and your child are second cosins. Your first cousin's grandshild and your child are second cousins, once removed. Your second cousin's child and your child are third cousins. Your second cousin's grandchild and your child are third cousins, once removed.
Your second cousin's siblings are also your second cousins. The children of your second cousins are your second cousins, once removed.
Your child and your great nephew's parents would be first cousins. Their children would then be second cousins. And if they have children, they will be third cousins.
Your daughter and your sister's child are first cousins. Your daughter and your sister's grandchild are first cousins, once removed.
Your first cousin's child is your first cousin once removed. Your second cousin's child is your second cousin, once removed.
They are of no blood relation. But they are cousins by marriage or 'step-cousins' as such.
Your daughter and your niece are first cousins. Your daughter than your niece's son are first cousin's once removed. Your daughter's child and your niece's child are second cousins to each other.