An ancient name for two promontories on either side of the Strait of Gibraltar (the Rock of Gibraltar and Mount Acho in Ceuta), held by legend to have been parted by the arm of Hercules.
Definition of Pillars of Hercules in US English:
Pillars of Hercules
proper noun
An ancient name for two promontories on either side of the Strait of Gibraltar (the Rock of Gibraltar and Mount Acho in Ceuta), held by legend to have been parted by the arm of Hercules.