[PeppyGPhiB]

Here is how it's been explained to me. The word "sorority," coined for my organization, means sisterhood in latin. Some sororities decided that it made no sense to have a greek name, yet adopt the new latin "sorority" label. So, they decided to stick with "fraternity." However since "fraternity" is also latin, I don't understand this explanation.

I think it could just be because "fraternity" was an accepted, well-known term, and so some sororities decided to call themselves "fraternities" because they figured outsiders would better understand what their organization was if they had that label.