The most common and most likely answer to this crossword clue is the 8 letter word TRAILING
I've seen this crossword clue in The Daily Telegraph
T
R
A
I
L
I
N
G
More clues leading to the result TRAILING
Buddy explains!

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 TRAILING mean?
TRAILING verb- To follow behind (someone or something); to tail (someone or something).
- To drag (something) behind on the ground.
- To leave (a trail of).
- To show a trailer of (a film, TV show etc.); to release or publish a preview of (a report etc.) in advance of the full publication.
- To hang or drag loosely behind; to move with a slow sweeping motion.
- To run or climb like certain plants.
- To drag oneself lazily or reluctantly along.
- To be losing, to be behind in a competition.
- To carry (a firearm) with the breech near the ground and the upper part inclined forward, the piece being held by the right hand near the middle.
- To flatten (grass, etc.) by walking through it; to tread down.
- To take advantage of the ignorance of; to impose upon.
- Fabric or other material that trails.
- (of points and crossovers) That converges in the direction of travel.
- That which is attached and pulled behind.