The most common and most likely answer to this crossword clue is the 7 letter word SINUOUS
I've seen this crossword clue in The Times
S
I
N
U
O
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S
More clues leading to the result SINUOUS
Buddy explains!

The straight part
We know that "Devious" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case devious = sinuous.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 SINUOUS mean?
SINUOUS adjective- Having curves in alternate directions; meandering.
- Moving gracefully and in a supple manner.
- Morally crooked; shifty.