Run off with high jumper, you say? (4)
I believe the answer is:
flee
'run off' is the definition.
(thesaurus)
'jumper you say?' is the wordplay.
'jumper' becomes 'flea' (something that jumps).
'you say?' shows a homophone (sound like).
'flea' is a homophone of 'FLEE'.
'with high' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
(Other definitions for flee that I've seen before include "head for the hills" , "Run quickly away" , "rush" , "Cut and run" , "Do a runner" .)