The most common and most likely answer to this crossword clue is the 9 letter word EMPHASISE
I've seen this crossword clue in The Daily Telegraph
E
M
P
H
A
S
I
S
E
More clues leading to the result EMPHASISE
- Impasse he cultivated, causing stress
- Stress when one supports English speed limits in Shropshire
- Space on island found during time of stress
- Drive home I see as tricky, maintaining a measure of speed
- Unfortunately, see mishap causing stress
- Worried MP? Ease his stress
- Stress stage is entered after the setter suffers withdrawal
- I see MP has exotic accent
- Stress English pies and mash must be cooked
- Note hip seams split by stress
Buddy explains!

The straight part
We know that "accent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case accent = emphasise.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 EMPHASISE mean?
EMPHASISE verb- To stress, give emphasis or extra weight to (something).