The most common and most likely answer to this crossword clue is the 9 letter word DIACRITIC
I've seen this crossword clue in Financial Times
D
I
A
C
R
I
T
I
C
More clues leading to the result DIACRITIC
- Molière has one to help upcoming reviewer
- Nearly ring reviewer, indicating change in sound
- Buñuel has one to relieve revolutionary reviewer
- I’d upset a judge? Could be grave
- Helper sent up judge’s accent
- Accent possibly declared “awful” by reviewer
- Maybe grave judge backs withdrawing help
- Help over judge’s accent?
- Distinguishing reportedly awful reviewer
- Mark to take last breath finding fault audibly?
Buddy explains!
The straight part
We know that "Could be grave" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case could be grave = diacritic.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
DIACRITIC noun- A special mark added to a letter to indicate a different pronunciation, stress, tone, or meaning.
- Distinguishing
- Denoting a distinguishing mark applied to a letter or character.