Portal

A door or gate; hence, a way of entrance or exit, especially one that is grand and imposing.

The lesser gate, where there are two of different dimensions.

Formerly, a small square corner in a room separated from the rest of the apartment by wainscoting, forming a short passage to another apartment.

By analogy with the French portail, used by recent writers for the whole architectural composition which surrounds and includes the doorways and porches of a church.

The space, at one end, between opposite trusses when these are terminated by inclined braces.

A prayer book or breviary; a portass.

Of or pertaining to a porta, especially the porta of the liver; as, the portal vein, which enters the liver at the porta, and divides into capillaries after the manner of an artery.

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."