The most common and most likely answer to this crossword clue is the 7 letter word AINTREE
I've seen this crossword clue in The Times
A
I
N
T
R
E
E
More clues leading to the result AINTREE
- After beginning of August change entire course
- A popular plant for a racecourse
- Horseracing venue isn't gratis, except for female
- Commonly, isn't starter excluded from complimentary course?
- Trainee jumping racecourse
- Racecourse area popular with elder, for example
- Racecourse isn’t available when source of funding is lost
- Chair here
- Course isn’t on English
- Trainee in crash course
Buddy explains!

The straight part
We know that "racecourse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case racecourse = aintree.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.