The most common and most likely answer to this crossword clue is the 7 letter word DENIALS
I've seen this crossword clue in Financial Times
D
E
N
I
A
L
S
More clues leading to the result DENIALS
Buddy explains!

The straight part
We know that "Rebuffs" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rebuffs = denials.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 DENIALS mean?
DENIALS noun- The negation in logic.
- A refusal to comply with a request.
- An assertion of untruth.
- Refusal to believe a problem exists
- A defense mechanism involving a refusal to accept the truth of a phenomenon or prospect.