Penelope didn't hide but ran off to marry (6)
I believe the answer is:
eloped
'ran off to marry' is the definition.
(I've seen this in another clue)
'penelope didn't hide' is the wordplay.
'hide' indicates a hidden word.
'ELOPED' is hidden in the letters of 'penelope didnt'.
'but' is the link.
(Other definitions for eloped that I've seen before include "Ran away to get married" , "Ran away to marry" , "Went off" .)