The most common and most likely answer to this crossword clue is the 3 plus 4 letter word THE OAKS
I've seen this crossword clue in The Daily Telegraph
T
H
E
O
A
K
S
More clues leading to the result THE OAKS
- Classic Kojak, when describing his head!
- Race heats OK after review
- One of the Dragons gets return of 18d
- Sports event similar toThe Ashes?
- Hot saké prepared? That’s a classic!
- Those guys briefly ahead of heavy drinker dropping first to last in race
- A classic article on timber trees
- Perhaps a Greek style of music reflects sports event
Buddy explains!

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