according to Mrs. Byrne's Dictionary, this is an abbreviation of
FASt GROwing Language of Initialisms and Acronyms

I'm sure some of you have discovered that you can find this referenced widely* on the 'net,
but I can't locate any other source or origination for it...


p.s. - this round of hogwash™ is going to take a while for me to score, so don't hold your breath.