The most common and most likely answer to this crossword clue is the 5 letter word ARDOR
A
R
D
O
R
More clues leading to the result ARDOR
Buddy explains!

The straight part
We know that "passion for his country" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case passion for his country = ardor.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 ARDOR mean?
ARDOR noun- Great warmth of feeling; fervor; passion.
- Spirit; enthusiasm; passion.
- Intense heat.