Your first cousin's second cousin may be your second cousin as well, or may not be related to you at all.
Your first cousin's children are your first cousins, once removed. They are your children's second cousins. Your second cousin's children are your second cousins, once removed. They are your children's third cousins. And so forth.
Your grandmother is first cousins with cousin. Your parent would be the second cousin of the cousin's son. That would make you second cousins once removed.
Your children and your first cousin's children are second cousins. Your children and your second cousin's children are third cousins. And so forth.
Your first cousin's child is your first cousin once removed. Your second cousin's child is your second cousin, once removed.
second-cousin
Your grandmother is first cousins with cousin. Your parent would be the second cousin of the cousin's son. That would make you 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 first cousin's daughter and you are first cousins, once removed. Your first cousin's children and your children will be second cousins to each other.
Your first cousin's daughter is your first cousin, once removed. Your child and your first cousin's daughter are second cousins to each other.
Your daughter and your first cousin are first cousins, once removed, to each other. Your daughter and your second cousin are second cousins, once removed, to each other.
Your first cousin's son and your children are second cousins to each other. Your second cousin's son and your children are third cousins to each other.
Your daughter and your first cousin's children are second cousins to each others.