The most common and most likely answer to this crossword clue is the 4 letter word WOLD
W
O
L
D
Buddy explains!
The straight part
We know that "Upland country" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case upland country = wold.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 WOLD mean?
WOLD noun- An unforested or deforested plain, a grassland, a moor.
- A wood or forest, especially a wooded upland.
- Old.