The most common and most likely answer to this crossword clue is the 11 letter word CHANTICLEER
I've seen this crossword clue in The Daily Telegraph
C
H
A
N
T
I
C
L
E
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R
Buddy explains!
The straight part
We know that "One to crow" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one to crow = chanticleer.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 CHANTICLEER mean?
CHANTICLEER noun- A domestic rooster or cock, especially in fables and fairy tales.
- To make the crowing sound of a cock.
- To crow in exultation.