The most common and most likely answer to this crossword clue is the 9 plus 6 letter word COLLISION COURSE
I've seen this crossword clue in The Daily Telegraph
C
O
L
L
I
S
I
O
N
C
O
U
R
S
E
More clues leading to the result COLLISION COURSE
- Crash out of this?
- Hit track a potential smash
- The road to ruin?
- Crash lectures, a sign of imminent trouble?
- Cornelius is cool changing route that would lead to conflict
- Crash studies lead to inevitable conflict
- Cornelius is cool about opposing philosophies leading to conflict
- Uncompromising approach that leads to things piling up
Buddy explains!
The straight part
We know that "Uncompromising approach that leads to things piling up" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case uncompromising approach that leads to things piling up = collision course.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.