The most common and most likely answer to this crossword clue is the 8 letter word SHEEPDOG
I've seen this crossword clue in The Times
S
H
E
E
P
D
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G
More clues leading to the result SHEEPDOG
- Go, with speed, running round front of herd? One might
- One or two animals in the field?
- One put on trial, eg, hoped thus finally to reform
- Followers pursue triallist perhaps
- In barn record calamity on field for farm worker
- . Hogs peed all over farmer’s best friend
- Herder: ‘Say nothing terribly deep or grand, initially’
- Best friend that works in, say, Cambridge track?
- Farm animal going through hedge so clumsily, beginning to panic
- Followers pursue trialist perhaps
Buddy explains!

The straight part
We know that "triallist perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case triallist perhaps = sheepdog.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 SHEEPDOG mean?
SHEEPDOG noun- A breed of dog, used for herding sheep.
- A breed of dog used for guarding sheep.
- A chaperon; an adult who accompanies other people in a supervisory role.
- (police) A police officer.
- To chaperon or shepherd.