The most common and most likely answer to this crossword clue is the 7 letter word CORRUPT
I've seen this crossword clue in The Sunday Telegraph
C
O
R
R
U
P
T
More clues leading to the result CORRUPT
- Sound contented, getting back into bed unclean
- Sound of satisfaction turning over in bed not to be trusted
- My rugby training base
- Sound of contentment lying around in bed that’s crooked
- Criminal with contented sound turned over in bed
- Beastly sound arising in bed for doctor
- Immoral bishop’s high during function
- Pervert to produce contented sound climbing into bed
- Either side of cooker with raised temperature? That’s not good
- Spoiled queen run out of bed, having broken one
Buddy explains!

The straight part
We know that "not good" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case not good = corrupt.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 CORRUPT mean?
CORRUPT verb- To make corrupt; to change from good to bad; to draw away from the right path; to deprave; to pervert.
- To become putrid, tainted, or otherwise impure; to putrefy; to rot.
- To debase or make impure by alterations or additions; to falsify.
- To waste, spoil, or consume; to make worthless.
- In a depraved state; debased; perverted; morally degenerate; weak in morals.
- Abounding in errors; not genuine or correct; in an invalid state.
- In a putrid state; spoiled; tainted; vitiated; unsound.