The most common and most likely answer to this crossword clue is the 11 letter word BELEAGUERED
I've seen this crossword clue in The Times
B
E
L
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A
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More clues leading to the result BELEAGUERED
Buddy explains!
The straight part
We know that "caused vexation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case caused vexation = beleaguered.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 BELEAGUERED mean?
BELEAGUERED verb- To besiege; to surround with troops.
- To vex, harass, or beset.
- To exhaust.
- Besieged; surrounded by enemy troops.
- Beset by trouble or difficulty.