Run off with east European, heading north (5)
I believe the answer is:
elope
'run off' is the definition.
(I know that run off can be written as elope)
'with east european heading north' is the wordplay.
'with' says to put letters next to each other.
'east' becomes 'E' (synonyms).
'european' becomes 'pole' (someone from Poland).
'heading north' says the letters should be written in reverse.
'e' next to 'pole' is 'epole'.
'epole' reversed gives 'ELOPE'.
(Other definitions for elope that I've seen before include "Run away secretly to marry" , "Bolt" , "Run off with Mr/Ms Right" , "(Lovers) run away" , "Run away together" .)