Fortarded is essentially retarded FORTRAN. This generally can be taken to mean any FORTRAN versions predating Fortran 90. Although a dedicated FORTRAN programmer can write Fortarded in any version of FORTRAN.

Someone who creates an alternate meaning for a word so he can use it on Facebook

A retarded fortnite player that uses shotguns and smgs to fucking kill you they also use those guns as toys

The same meaning as Retard yet used in public to make fun of people without offending those who are sensitive to the use of the word Retard