The most common and most likely answer to this crossword clue is the 8 letter word OPTIMISM
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The straight part
We know that "confidence" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case confidence = optimism.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 OPTIMISM mean?
OPTIMISM noun- A tendency to expect the best, or at least, a favourable outcome
- The doctrine that this world is the best of all possible worlds
- The belief that good will eventually triumph over evil