Portal - A Web site that provides a gateway to other 
Web sites.

Eric Donald Hirsch, Joseph F. Kett, and James S. 
Trefil. The New Dictionary of Cultural Literacy: 
What Every American Needs to Know. Third Edition. 
Copyright © 2002. All rights reserved. Houghton 
Mifflin (Boston).



por·tal      (pôr'tl, po-r'-)  Pronunciation Key 
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 
porta-le, city gate, from neuter of porta-lis, of a gate, 
from Latin porta, gate; see per-2 in 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 ba-b 
(ekalli), gate (of the palace), umbilical fissure of the 
liver (next to the transverse fissure).]

The American Heritage® Dictionary of the English 
Language. Fourth Edition. Copyright © 2006 by 
Houghton Mifflin Company. All rights reserved. Houghton 
Mifflin (Boston).

A time portal was a gateway though which a person 
could time travel.

In the 31st century, one of the ways a Temporal agent 
could travel back in time was through time portals.

When Daniels took Jonathan Archer to the future to 
protect him, he destabilized the timeline, destroying 
the future he knew. This also meant Earth never 
developed time travel technology, so there were no 
time portals to send Captain Archer back to 2152. 
(ENT: "Shockwave")

James Kirk, Leonard McCoy and Spock traveled back in 
time to 1930 using the Guardian of Forever, an ancient 
Time Portal located on an ancient world. (TOS: "The 
City on the Edge of Forever")

Kirk, McCoy and Spock later traveled back into 
Sarpeidon's past through a time portal which was 
controlled by the atavachron. The time period chosen 
was based on the verism tape that was at the time 
accessed. (TOS: "All Our Yesterdays")

The alien inhabitants of Devidia II used a space/time 
portal to travel to nineteenth-century San Francisco. 
(TNG: "Time's Arrow")

Time portals have also been found on the Bajoran world 
Golana. They belonged to a now extinct race. Molly 
O'Brien fell into one of these portals in late 2374. 
(DS9: "Time's Orphan") 

"Time Portal," Memory Alpha, the Star Trek Wiki 
[Retrieved on December 25, 2008]