Hill, perhaps, rambler goes up (5)
I believe the answer is:
damon
'hill perhaps' is the definition.
(racing driver Damon Hill)
'rambler goes up' is the wordplay.
'rambler' becomes 'nomad' (someone who roams or rambles).
'goes up' shows that the letters should be reversed in order.
'nomad' in reverse letter order is 'DAMON'.
(Other definitions for damon that I've seen before include "faithful friend" , "Writer Runyon's first name" , "Matt --, US actor" , "Pythias's friend" .)