The most common and most likely answer to this crossword clue is the 5 letter word JOYCE
I've seen this crossword clue in Financial Times
J
O
Y
C
E
More clues leading to the result JOYCE
- Happiness at clearing out corpse of wartime traitor
- Female caught between happiness and ecstasy
- Irish author finding happiness, having Catholic education, initially
- Novelist’s happiness with church
- Great happiness: caught European dictator’s spokesman
- Author’s delight over cruise, needing vacation
- Transport covers for cycle
- Irish writer gets great pleasure attending church
- Novelist’s delight over church
- Young Conservative introduced to Stalin wrote a book 100 years ago about the other people mentioned here?
Buddy explains!
The straight part
We know that "wartime traitor" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wartime traitor = joyce.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.