To be "once removed" from a cousin means you are separated by one generation. The number before "removed" will always represent the number of generations you are separated ("removed") from the cousin. The following cousins removed chart illustrates how first cousins share a grandparent, second cousins share a great-grandparent, third cousins share a great-great-grandparent, and fourth cousins share a 3rd-great-grandparent. In the cousin family hierarchy, the term "removed" indicates the separation of a generation. Your first cousin is the same generation as you are, so your first cousin once removed would be either your parent's first cousin or your first cousin's child.
