Crossword Genius

Much drier for a guy on a horse (6)

Ross

I believe the answer is:

arider

I'm a little stuck... Click here to teach me more about this clue!

'on a horse' is the definition.
I can't tell whether this definition defines the answer.

'much drier for a guy' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'drier' is 'rider' which is located in the answer.
'a' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.
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