The most common and most likely answer to this crossword clue is the 6 letter word SPRINT
I've seen this crossword clue in The Guardian
S
P
R
I
N
T
More clues leading to the result SPRINT
- Move fast, beginning to study engraving, perhaps
- Small print run
- Run off after second short race
- Small photo of race
- Move fast through detailed terms and conditions?
- Make an impression, following second career
- Run very fast time at the end of curtailed season
- … typo Military Intelligence overlooked — dash!
- Sons run off, and do so quickly
- Run quickly, son — run off!
Buddy explains!

The straight part
We know that "race" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case race = sprint.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 SPRINT mean?
SPRINT noun- A short race at top speed.
- A burst of speed or activity.
- In Agile software development, a period of development of a fixed time that is preceded and followed by meetings.
- To run, cycle, etc. at top speed for a short period,