The most common and most likely answer to this crossword clue is the 5 letter word PACER
P
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R
More clues leading to the result PACER
- Trained horse is very good in pair
- Horse, one in the middle of Cyprus
- Power with which star runs — probably a runner to fade?
- Horse seen from uppermost part of pear tree
- Horse heading for poisonous shrub
- Going north, run over horse
- Hidden in gap, a certain type of horse
- One not expecting to win, top performer having entered prize ring
- Horse given last of syrup
- Publicity about star horse not very good?
Buddy explains!

The straight part
We know that "horse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case horse = pacer.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 PACER mean?
PACER noun- One who paces.
- In harness racing, a horse with a gait in which the front and back legs on one side take a step together alternating with the legs on the other side; as opposed to a trotter.
- A pacemaker.
- A mechanical pencil.