Noun:
1: portal a grand and imposing entrance (often extended metaphorically); "the portals of the cathedral"; "the portals of heaven"; "the portals of success"
2: portal site, portal a site that the owner positions as an entrance to other sites on the internet; "a portal typically has search engines and free email and chat rooms etc."
3: hepatic portal vein, portal vein, vena portae, portal a short vein that carries blood into the liver