The most common and most likely answer to this crossword clue is the 7 letter word EVEREST
E
V
E
R
E
S
T
More clues leading to the result EVEREST
- Peak that’s most difficult, not starting out
- Mountain always is found in France
- Highest point is always estimated
- Sherpa's first to leave most demanding mountain
- Mountain most demanding in leader’s absence
- Young hare loses head, circling top of snowy mountain
- High point eclipsed by severe storm
- First lady to settle on a mountain
- Highest point for serviette without it disintegrating
- Most dangerous, heading off to mountain
Buddy explains!
The straight part
We know that "It’s forbidding, top to bottom, on Tibet’s southern border" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case it’s forbidding, top to bottom, on tibet’s southern border = everest.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.