The most common and most likely answer to this crossword clue is the 8 letter word DISSUADE
I've seen this crossword clue in The Guardian
D
I
S
S
U
A
D
E
More clues leading to the result DISSUADE
Buddy explains!

The straight part
We know that "Put off" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case put off = dissuade.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 DISSUADE mean?
DISSUADE verb- To convince not to try or do.