The most common and most likely answer to this crossword clue is the 6 letter word THWACK
I've seen this crossword clue in The Daily Telegraph
T
H
W
A
C
K
More clues leading to the result THWACK
- Hard-hitting report from Scouse pal on Thursday
- … With such a noise? Watch out, fourth of punkahs following
- Change course, taking in hot western belt
- Strike the short Scouser’s mate
- Beat time with mediocre snares
- Finish off roast chop sandwiches with buffet
- What KFC doesn’t have following mixed buffet?
- Strike for the patchwork processed by the missing pro
- Slap broken watch with bottom of brick
Buddy explains!

The straight part
We know that "buffet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case buffet = thwack.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 THWACK mean?
THWACK noun- The act of thwacking; a strike or blow, especially with a flat implement.
- A heavy slapping sound.
- To hit with a flat implement.
- To beat.
- To fill to overflow.