The most common and most likely answer to this crossword clue is the 9 letter word SYMPOSIUM
I've seen this crossword clue in The Times
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More clues leading to the result SYMPOSIUM
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The straight part
We know that "Meeting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case meeting = symposium.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 SYMPOSIUM mean?
SYMPOSIUM noun- A conference or other meeting for discussion of a topic, especially one in which the participants make presentations.
- A drinking party in Ancient Greece, especially one with intellectual discussion.