The most common and most likely answer to this crossword clue is the 6 letter word PORTAL
I've seen this crossword clue in The Sunday Telegraph
P
O
R
T
A
L
More clues leading to the result PORTAL
- Left in front of a large entrance
- One entering left twice– a grand entrance
- Entrance men starting to travel in China
- Left beside a large, imposing gate
- Entrance friend eating golden treacle to begin with
- Opening wine going with nearly everything
- Left by a student entrance
- Part of passport allowing entrance
- Opening place to go for pop festivals? Loves to get away
- Lawyer in Venice spent one fifty for website?
Buddy explains!

The straight part
We know that "entrance" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case entrance = portal.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PORTAL mean?
PORTAL noun- An entrance, entry point, or means of entry.
- A website or page that acts as an entrance to other websites or pages on the Internet.
- A short vein that carries blood into the liver.
- A magical or technological doorway leading to another location, period in time or dimension.
- A lesser gate, where there are two of different dimensions.
- Formerly, a small square corner in a room separated from the rest of an apartment by wainscoting, forming a short passage to another apartment.
- A grandiose and often lavish entrance.
- (bridge-building) The space, at one end, between opposite trusses when these are terminated by inclined braces.
- A prayer book or breviary; a portass.
- Of or relating to a porta, especially the porta of the liver.