The most common and most likely answer to this crossword clue is the 8 letter word INSOLENT
I've seen this crossword clue in The Times
I
N
S
O
L
E
N
T
More clues leading to the result INSOLENT
- Offensive involved Nelson aboard it
- Fresh, in water off the Isle of Wight
- Fresh sailing just off the south coast of England?
- Edited lines not causing offence?
- Suspect in stolen lippy
- Playing tennis, keeping ball on line is rude
- On the way to Ryde, being cheeky
- Disrespectful, having capsized off the South coast?
- Certainly too fresh in Hampshire strait
- Rude, popular and very fast
Buddy explains!

The straight part
We know that "causing offence?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case causing offence? = insolent.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 INSOLENT mean?
INSOLENT noun- A person who is insolent.
- Insulting in manner or words.
- Rude.