Your son and your first cousin's son are second cousins to each other.
Your first cousin's son is also YOUR first cousin, once removed.
Your first cousin's child is your son's second cousin.
Your second cousin's child is your son's third cousin.
your cousin's child will be your 2nd cousin.
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.