Your first cousin's child is your first cousin once removed.
Your children and that child will be second cousins to each other.
This poster above is incorrect. If you have the same grandparents as someone on either side, they are your first cousins. Your first cousins once removed would be if your great-grandparents were someone else's grandparents. Your second cousins are if you have the same great grandparents as someone. etc.
The child of your first cousin once removed is your first cousin twice removed if your first cousin once removed is the child of your first cousin.
The child of your first cousin once removed is your second cousin if your first cousin once removed is your parent's first cousin.
The child of your first cousin once removed is your first cousin twice removed if your first cousin once removed is in a younger generation that you.
If your first cousin once removed is in an older generation than you, the child is your second cousin.
You and the child of your first cousin are first cousins once removed.
You and your first cousin's child are first cousins, once removed, to each other.
The child of your second cousin is your second cousin, once removed.
The child of your second cousin is your child's third cousin.
The child of your third cousin is your third cousin, once removed.
Your grandmother's first cousin's child is your parent'ssecond cousin and your second cousin, once removed.
Your mother's first cousin's child is your second cousin.
You are first cousins once removed to each other.
You are first cousins once removed to each other.
You and the child of your first cousin are first cousins once removed.You and your first cousin's child are first cousins, once removed, to each other.
Your cousin (if a first cousin) and your child are first cousins once removed.
Your child and your first cousin are first cousins, once removed to each other.
Your first cousin's child would be your second cousin
Your child and your first cousin's child are second cousins. A full generation is another set of cousins. For example, the second cousins' children will be third cousins, etc. Now here is the tricky part. You are a first cousin once removed to your cousin's child and your cousin is a first cousin once removed from your child.
Your first cousin and your grandchildren (your child's children) are first cousins once removed.
Your child and your sister's children are first cousins. Your grandchild and your sister's children are first cousins once removed.
Assuming both children are on the same side of the family, your child's first cousin is a second cousin to your first cousin's child. Your child is also a second cousin to your first cousin's child. Your child can have first cousins who are not related to your first cousin and thus not related to your first cousin's child.
You and your uncle's child are first cousins to each other. You and your uncle's grandchild are first cousins, once removed, to each other.
Your first cousin's child is your child's second cousin. Your second cousin's child is your child's third cousin. Your third cousin's child is your child's fourth cousin. and so forth
Your child and your first cousin's child are second cousins. Your child and your second cousin's child are third cousins to each other.