The most common and most likely answer to this crossword clue is the 7 letter word DEVIOUS
I've seen this crossword clue in The Daily Telegraph
D
E
V
I
O
U
S
More clues leading to the result DEVIOUS
- Shifty of you French to pinch Naomi’s bottom
- Use Ovid’s formulation for calculating
- Artful dodgy videos, done inside
- Crafty journalist returned acknowledgements of debt after third of November
- Dodgy video disturbed you and me
- I have risen in party — American playing dirty
- God suppresses a number of Romansscheming
- Sneaky editor returns five notes
Buddy explains!

The straight part
We know that "playing dirty" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case playing dirty = devious.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 DEVIOUS mean?
DEVIOUS adjective- Cunning or deceiving, not straightforward or honest, not frank
- Roundabout, circuitous, deviating from the direct or ordinary route