The degree of cousinhood denotes the number of generations between two cousins and their nearest common ancestor.
First cousins share a grandparent.
Second cousins share a great-grandparent.
Third cousins share a great-great-grandparent...and so on. Your first cousin once removed is the child or parent of your first cousin.
Your first cousin twice removed is the grandchild or grandparent parent of your first cousin.
Your second cousin once removed is the child or parent of your second cousin.
Your second cousin twice removed is the grandchild or grandparent parent of your second cousin.
Your third cousin once removed is the child or parent of your third cousin.
Your third cousin twice removed is the grandchild or grandparent parent of your third cousin...and so one.
The term removed refers to the number of generations separating the cousins themselves.