The most common and most likely answer to this crossword clue is the 15 letter word TEMPERAMENTALLY
I've seen this crossword clue in Financial Times
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More clues leading to the result TEMPERAMENTALLY
- Harden attitudes initially in the mind like a prima donna
- According to mood, modify account having secured the last word
- Harden attitudes initially in the mind, like a prima donna
- Kind of paint people match — that’s how artists are supposed to behave
- Tune ‘Let it Be’ with score showing extremes of emotion
- My lament: prelate being unstable in terms of emotional disposition
- Paint valets with count in a moody way
Buddy explains!
The straight part
We know that "like a prima donna" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case like a prima donna = temperamentally.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.