The most common and most likely answer to this crossword clue is the 9 letter word FISHTAILS
F
I
S
H
T
A
I
L
S
Buddy explains!
The straight part
We know that "slides back and forth" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case slides back and forth = fishtails.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 FISHTAILS mean?
FISHTAILS noun- The tail of a fish, or an object resembling this.
- The skidding of the back of a vehicle from side to side.
- A kind of chisel with a flared blade.
- To swing the back of a vehicle (originally an aircraft) from side to side.
- To cause the back of (a vehicle) to swing from side to side.
- To move with the tail swinging from side to side in this way.