The most common and most likely answer to this crossword clue is the 9 letter word OKEY-DOKE
O
K
E
Y
-
D
O
K
E
More clues leading to the result OKEY-DOKE
Buddy explains!

The straight part
We know that "fine" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fine = okey-doke.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.
Crossword Answer definitions
OKEY-DOKE interjection- OK