portal-n; 3 Senses

Sense Number 1: an expansive architectural entryway, e.g., big door

Commentary: PORTAL[+entity][+structure][+entryway][+architectural][+door][+expansive] PORTAL[+entity][+structure][+entryway][+architectural][+door][+approach][+tunnel] PORTAL[+entity][+structure][+entryway][+architectural][+door][+approach][+bridge]

The portals of the cathedral had carved panels depicting scenes from the Bible.
The very portals of heaven seemed to open up during the thunderstorm. (figurative extension)
An accident at the portal of the main bridge has traffic backed up for miles.
Having a bestseller has opened the portals of success to the young author. (figurative extension)

WordNet 3.0 Sense Numbers: 1

Sense Number 2: a primary website which links to other sites

Commentary: PORTAL[+entity][+structure][+entryway][+symbolic][+website][+linking]

John designed the portal of his company's website.
Mary's browser blocks access to certain adult-themed portals.
It's a nice portal to all sorts of links to websites about gardening and home decorating.

WordNet 3.0 Sense Numbers: 2

Sense Number 3: a major vein in the body

Commentary: PORTAL[+entity][+structure][+entryway][+biological][+vein][+major]

The portal system carries blood from abdominal organs to the liver.
The patient suffers from portal hypertension.

WordNet 3.0 Sense Numbers: 3