Runaway of a sort (6)
I believe the answer is:
eloper
'runaway of a sort' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for eloper that I've seen before include "Runaway 27 [SWEETHEART]" , "One running off to marry" , "Lover escaping" , "One keen to marry" , "One running away to get married" .)