Haggard jockey? (5)
I believe the answer is:
rider
I believe this clue is a double definition.
'haggard' is the first definition.
(novelist H Rider Haggard)
'jockey?' is the second definition.
(horse rider)
(Other definitions for rider that I've seen before include "One on a horse or cycle" , "one making journey" , "Jury's recommendation" , "Additional bit" , "supported by an Arab, perhaps" .)