The most common and most likely answer to this crossword clue is the 8 letter word OVERLAND
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More clues leading to the result OVERLAND
Buddy explains!

The straight part
We know that "across country" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case across country = overland.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 OVERLAND mean?
OVERLAND noun- (travel) a trip by land between the UK and the Indian Sub-continent or Australia, or between the UK and South Africa.
- To transport (especially sheep or other farm animals) over land
- To travel across land
- By or across land, especially of travel
- Over, across, or by land.