The most common and most likely answer to this crossword clue is the 11 letter word CHLORINATED
I've seen this crossword clue in The Guardian
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Buddy explains!
The straight part
We know that "Sort of chicken" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sort of chicken = chlorinated.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 CHLORINATED mean?
CHLORINATED verb- To add chlorine to (something, especially water, to purify it; or an auriferous substance, to extract gold from it).
- Of water, that has had chlorine added to it to purify it.