por·tal 
(pôrtl)
(pôrtl)n.
1. A doorway, entrance, or gate, especially one that is large and imposing.
2. An entrance or a means of entrance: the local library, a portal of knowledge.
3. The portal vein.
4. A website considered as an entry point to other websites, often by being or providing access to a search engine.
adj.
1. Of or relating to the portal vein or the portal system.
2. Of or relating to a point of entrance to an organ, especially the transverse fissure of the liver, through which the blood vessels enter.
[Middle English, from Old French, from Medieval Latin portāle, city gate, from neuter of portālis, of a gate, from Latin porta, gate; see per-2 in the Appendix of Indo-European roots. N., sense 3 and adj., from New Latin porta (hepatis), transverse fissure (of the liver), literally gate of the liver, perhaps ultimately translation of Akkadian bāb (ekalli), gate (of the palace), umbilical fissure of the liver (next to the transverse fissure).]
portalShrine of Imam Reza
Mashhad, Iran