portal (n.)

late 14c., "gate, gateway," especially "the entire architectural treatment of the entrance and its surroundings of a cathedral or other grand building," from Old French portal "gate" (Modern French portail) and directly from Medieval Latin portale "city gate, porch," from neuter of portalis (adj.) "of a gate," from Latin porta "gate," from PIE *prta-, suffixed form of PIE root *per- (2) "to lead, pass over." The medical sense of "place where a drug, etc., enters or leaves the system" is by 1910.