The most common and most likely answer to this crossword clue is the 6 letter word DERAIL
I've seen this crossword clue in The Times
D
E
R
A
I
L
More clues leading to the result DERAIL
- Redirect Queen entering European parliament
- Read about beginnings of internet lawlessness? Go off line
- Redial incorrectly to come off the line
- Throw off course queen in foreign parliament
- Stop and give a lift to storyteller and journalist
- Throw off track?
- Stop queen entering Irish house
- Upset as a result of cover-up over a long period
Buddy explains!

The straight part
We know that "Stop" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stop = derail.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 DERAIL mean?
DERAIL noun- A device placed on railway tracks causing a train to derail.
- An instance of diverting a conversation or debate from its original topic.
- To cause to come off the tracks.
- To come off the tracks.
- To deviate from the previous course or direction.
- To cause to deviate from a set course or direction; derange.