The most common and most likely answer to this crossword clue is the 9 letter word COMPLETED
I've seen this crossword clue in The Guardian
C
O
M
P
L
E
T
E
D
Buddy explains!
The straight part
We know that "finished" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case finished = completed.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 COMPLETED mean?
COMPLETED verb- To finish; to make done; to reach the end.
- To make whole or entire.
- To call from the small blind in an unraised pot.
- Finished.