The most common and most likely answer to this crossword clue is the 10 letter word SUSPICIOUS
I've seen this crossword clue in Independent
S
U
S
P
I
C
I
O
U
S
More clues leading to the result SUSPICIOUS
Buddy explains!

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 SUSPICIOUS mean?
SUSPICIOUS adjective- Arousing suspicion.
- Distrustful or tending to suspect.
- Expressing suspicion