Run off for romance (5)
I believe the answer is:
elope
'run off for romance' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elope that I've seen before include "Run away together" , "escape" , "Run off with Mr/Ms Right" , "(Lovers) run away" , "Run away to Gretna Green?" .)