Half Cousins is a recognized legal term in many state laws. If fact, there are certain states that prohibit the marriage of first cousins but allow marriage of half cousins. Half cousins are defined as those sharing on one set, rather than two sets of the same grandparents. Regarding the "once removed" designation, it is my understanding that this indicates that two individuals are separated by one generation (one a generation older than the other) and would not have any relevance here. Jerry