Your first cousin's grandchild is your first cousin twice removed
Your first cousin's child is your "first cousin once removed", not, as many believe, your "second cousin". Second cousins are the children of first cousins, third cousins are the grandchildren of first cousins, and so on. Therefore, your cousin's son's son is your "first cousin twice removed". It's a generational thing, you see? First cousins are of the same generation. Second cousins are of the same generation...third cousins are of the same generation, and so on. "Once removed" refers to a cousin who is one generation down from yourself.
Cousine
Your uncle's sons and daughters are your first cousins.
third cousin once removed
They share a common Grandparent. That makes them first cousins.
Your granddaughter and your sister's grandson are second cousins.
Your first cousin is your son's first cousin once removed.
basiclly there called brothers .-.-.-.-.-.-. basically* for one... and two no, they wouldn't be called brothers. If it was their parents sons then yeah, but if it's the sons of brothers then they'd be cousins. That's practically like saying one brother got married and had a son, then the other did too and had a son as well. The relation of the sons would be cousins.
Your son and your nephew are first cousins to each other. Their daughters are second cousins to each other.
Your mom and her uncle's son are cousins, of the same generation, first cousins. Your mom's uncle's son is your first cousin, once removed (by one generation). If he has children, they will be your second cousins. (Children of first cousins are second cousins to each other.)
Your cousins son will be your second cousin xx
Your father's first cousin's son is your second cousin. Your father's second cousin's son is your third cousin. If your are asking about your fathers cousins who are in a removed cousin relationship to your father, their relationship to you be more complex, with two different possibilities in each case.
Your son and your niece are first cousins to each other. Your son and your niece's son are first cousins, once removed.