The most common and most likely answer to this crossword clue is the 7 plus 3 letter word TRAFFIC JAM
I've seen this crossword clue in The Times
T
R
A
F
F
I
C
J
A
M
More clues leading to the result TRAFFIC JAM
- Buying and selling stuff, lines not shifting?
- One extends journey to trade with Jamaica
- A rift developed about fine cloudy preserve – no-one moves in it
- The preserve of the frustrated driver?
- Symptom of arterial blockage?
- It causes a hold-up in dealings with crowd
- Trade spread, creating congestion
- Run with pack, causing arterial blockage
- Horns may be heard during its slow movement
- What WI members do in a queue?
Buddy explains!
The straight part
We know that "lines not shifting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case lines not shifting = traffic jam.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.