Your child and your first cousin's child are second cousins becase they share the same common ancester(s) and that is your Grandparents, your child's Great Grandparents. You and your cousin's child are first cousins once removed becasue the both of you are in different generations and have no ancesters in common and the 'once removed' means that they came one generation after you.
They share a common grandparent. That makes them first cousins.
Your cousin's baby would be your second cousin
Your baby and your cousins are first cousins once removed to each other. You baby and your second cousins are second cousins once removed to each other.
Second cousins.
The relationship between your sister's (or brother's) child and your cousin is the same as the relationship between your child and your cousin. Your child and your first cousin are first cousins, once removed. Your child and your second cousin are second cousins, once removed, and so forth.
You and your first cousin's son are first cousins, once removed.
Your cousins child is your first cousin once removed.
Your uncle's first cousins are also your parent's first cousins and so are your first cousins once removed. Similarly his second cousins are your second cousins once removed.
If it is not your common grandparent, there is no relationship.
If two people are first cousins, their children are second cousins. If two people are fifth cousins, their children are sixth cousins.
Your children and your first cousin's children are second cousins.
second cousins to his cousin's children, you'd be third cousins