1. a grand and imposing entrance (often extended metaphorically)
e.g. the portals of the cathedralthe portals of heaventhe portals of success
2. a short vein that carries blood into the liver
Synonym: portal veinhepatic portal veinvena portae
3. a site that the owner positions as an entrance to other sites on the internet
e.g. a portal typically has search engines and free email and chat rooms etc.
Synonym: portal site