The most common and most likely answer to this crossword clue is the 4 letter word ASIA
I've seen this crossword clue in The Times
A
S
I
A
More clues leading to the result ASIA
- Like one with a large landmass
- Continent as hypothetical person drinking unlimited kir
- Continent first of all in Africa, second is Antarctica
- A very large amount of land here in Kansas I acquired
- Part of the world, mostly unchanged area
- Huge land mass, like one close to Africa
- Ladies' man is regularly head over heels in this region
- Faustina regularly seen in vast region
- Part of Georgia is actually to the west of here
- Last 40% of ‘mercy killings’: most of world’s population
Buddy explains!
The straight part
We know that "vast region" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vast region = asia.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.