The most common and most likely answer to this crossword clue is the 9 letter word GOALPOSTS
I've seen this crossword clue in Financial Times
G
O
A
L
P
O
S
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S
More clues leading to the result GOALPOSTS
Buddy explains!
The straight part
We know that "what leading characters from Harlequins and Hull KR represent in their sports" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what leading characters from harlequins and hull kr represent in their sports = goalposts.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 GOALPOSTS mean?
GOALPOSTS noun- One of the two vertical side poles of a goal.
- The tall Y-shaped upright, now usually of fiberglass, at either end of the playing field, through which a football must go in order for a field goal to be scored. (They were originally H-shaped, with one wooden post on either side.)