The most common and most likely answer to this crossword clue is the 8 letter word STROPPED
I've seen this crossword clue in The Daily Telegraph
S
T
R
O
P
P
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D
More clues leading to the result STROPPED
Buddy explains!
The straight part
We know that "Sharpened" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sharpened = stropped.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 STROPPED mean?
STROPPED verb- To strap.
- (recorded since 1842; now most used) To hone (a razor) with a strop.
- To mark a sequence of letters syntactically as having a special property, such as being a keyword, e.g. by enclosing in apostrophes as in 'foo' or writing in uppercase as in FOO.