The most common and most likely answer to this crossword clue is the 4 letter word ASHE
I've seen this crossword clue in Independent
A
S
H
E
More clues leading to the result ASHE
- Some smashes for a Wimbledon champion
- American woman who once won Wimbledon
- Court winner remains for hearing
- Old court hero ultimately identifiable by cigar droppings
- Major Victor‘s a lady
- A female former Wimbledon champion
- What was that about following a second US sportsman?
- He’s a sporting champion
- American female tennis legend
- Legendary tennis player has changed game, ultimately
Buddy explains!

The straight part
We know that "Old court hero" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case old court hero = ashe.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.