Jockey a horse on dry ground (6)
I believe the answer is:
ashore
'on dry ground' is the definition.
(I've seen this in another clue)
'jockey a horse' is the wordplay.
'jockey' is an anagram indicator (the letters scramble or jockey around).
'a'+'horse'='ahorse'
'ahorse' anagrammed gives 'ASHORE'.
(Other definitions for ashore that I've seen before include "On(to) dry land" , "on terra firma" , "on the coast" , "Hoarse being no longer at sea" , "On land (as opposed to the sea)" .)