Which do you-all say it is?

Me-all says (and I left my copy of the WAD at home) that the name of the place is an eponym (well sort of, there seems to be some question as to whether it comes from Gebel-Tarik meaning "the mountain of Tarik" or Jabbar-altar "Jabbar's heights". Either way it's got eponymic tendencies) but if it's used to mean "any strong fortress" it's a toponym.