The most common and most likely answer to this crossword clue is the 9 letter word FERMENTED
I've seen this crossword clue in The Daily Telegraph
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More clues leading to the result FERMENTED
Buddy explains!
The straight part
We know that "Agitated" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case agitated = fermented.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 FERMENTED mean?
FERMENTED verb- To react, using fermentation; especially to produce alcohol by aging or by allowing yeast to act on sugars; to brew.
- To stir up, agitate, cause unrest or excitement in.
- Produced by fermentation.
- Of food or drink, turned sour due to unwanted fermentation.