The most common and most likely answer to this crossword clue is the 6 letter word CHOPPY
I've seen this crossword clue in The Guardian
C
H
O
P
P
Y
More clues leading to the result CHOPPY
- Rough bits apparently swapped by carpenter?
- Cold as a bouncer? That’s a bit rough
- Rough, getting caught having a taste of ale
- Dispense with pony on leaving with white horses
- Rough clubs like strong-flavoured alcohol
- Rough clubs with a beery whiff?
- Cold beer like this is rough!
- Like beer provided by clubs, a little rough
- Rough cut of meat — it comes out of pity
- Head of CAMRA’s description of some ales as rough
Buddy explains!

The straight part
We know that "a bit rough" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a bit rough = choppy.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 CHOPPY mean?
CHOPPY adjective- (of the surface of water) Having many small, rough waves.
- Discontinuous, intermittent.
- (of wind) Shifting, variable