The most common and most likely answer to this crossword clue is the 5 plus 3 letter word KNOCK OFF
I've seen this crossword clue in The Sunday Telegraph
K
N
O
C
K
O
F
F
More clues leading to the result KNOCK OFF
Buddy explains!
The straight part
We know that "finish work" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case finish work = knock off.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 KNOCK OFF mean?
KNOCK OFF noun- An imitation of something, particularly a well-known product, usually lower in quality and price than the original.
- A device in a knitting machine to remove loops from the needles.