The most common and most likely answer to this crossword clue is the 9 letter word CERTAINLY
I've seen this crossword clue in The Daily Telegraph
C
E
R
T
A
I
N
L
Y
More clues leading to the result CERTAINLY
Buddy explains!
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 CERTAINLY mean?
CERTAINLY adverb- In a way which is certain; with certainty.
- Without doubt, surely.
- An emphatic affirmative answer; of course.