This is 'gifted' backwards, and is an adjective reserved for:
1. the peculiar variety of being lame
that occurs among intellectually 'gifted' people who should know better. Used jokingly between fellow gifted people (usu. friends).
2. those who are actually very stupid (as in, the complete opposite of being gifted). A derogatory term very occasionally used for these people by the gifted ones, in times of extreme frustration or need.
1. Two jovial yet geeky classmates approach the library with handfuls of textbooks. One pushes against the entrance door which clearly reads "PULL". The other may comment: "Detfig!"
2. Moronic workmate insists on doing it his way, which obviously will not work. The gifted colleague may mutter: "So fucking DETFIG!"