GAF is an abbreviation for give a fuck While it doesn't not look abusive, you have read that for yourself. I received knowledge about this word when I went to school in class 8 hence I do not have any intellectual property rights ,due credits to the inventor. I though it was a silly abb. and I was reluctant to use it only to realize that I was using it more than anyone later in life which is why I'd like to make thos world a better place and do my bit .