The most common and most likely answer to this crossword clue is the 11 letter word ASSIGNATION
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The straight part
We know that "Scandalous date" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case scandalous date = assignation.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 ASSIGNATION mean?
ASSIGNATION noun- An appointment for a meeting, generally of a romantic or sexual nature.
- The act of assigning or allotting; apportionment.
- A making over by transfer of title; assignment.