With the word 'frat', it's just an abbreviation of fraternity. The analogies used to say that the act of abbreviating it (country and mother) really have no base. It all boils down to a respect issue. I know that any time I go into a fraternity's meeting to speak on anything, I always greet them with "hello gentlemen". Regardless of my having a great rapport with the group, I will always refer to them as gentlemen in a formal context. This may just be me, seeing as I tend to refer to my sisters, and other sorority members, as ladies when I see a group of them anywhere. It's something that I have ingrained into my daily vernacular and, as such, I don't give it a second thought. It's all about respect.
And now I'm done with my babbling. :) Have a good one all.

Of course I myself prefer a "fraternity" instead of "frat". I think all of the explanations are correct, and I just want to add a thing. It seems that "frat" is a degretory (sp?) term, and the comparison of this is "recruitment" instead of "rush". "Recruitment" sounds more professional than "rush".
I know the NPHC still use "frat" or "soror" or "rush", but I think they will change sometime in the future.

So I would appreciate people that use the respectful term of "fraternity" than frat. Even I have to explain this to our own alumni.

Just my .02 cents ;)

There's too many people here who say frat to correct them, so I'm over it.

I've always said frat and this is the first time I have ever heard anyone complain about it!!

I have said frat at times I think just b/c I was being lazy, but normally I always will say Fraternity. I had asked a couple of friends of mine why they like fraternity better one time and they pretty much told me what everyone is sayin here. its a respect thing, which I totally understand and to me its like its a big thing to say the whole word it doesnt take that much more energy people! lol ;)

Nichole