This term refers to a difference in generations; your first cousin's child is your first cousin once this
The child of your 
first cousin is also your first cousin once removed: your grandparent is that child's
... [DOC] [TLE] Defining Cousins - Homepages Rootsweb - Ancestry.com [PAR] If someone is your first cousin, then his or her child is your first cousin once 
removed.