The most common and most likely answer to this crossword clue is the 8 letter word COCKSURE
I've seen this crossword clue in The Daily Telegraph
C
O
C
K
S
U
R
E
More clues leading to the result COCKSURE
- Confident male squirmed oddly
- Arrogant male turning us on
- To turn up with petition around middle of afternoon is arrogant
- Swaggering, make better boxing punch first to last
- Arrogant bird? Yes!
- Annoyingly self-confident and certain to get the bird first
- Mate’s certainly arrogant
- Over-confident birds on river
- Overconfident birds on river
- Arrogant Rick’s on river
Buddy explains!
The straight part
We know that "Overconfident" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case overconfident = cocksure.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 COCKSURE mean?
COCKSURE adjective- Too confident; overconfident