Definitely safe or successful (4,3,3)
I believe the answer is:
home and dry
'definitely safe or successful' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for home and dry that I've seen before include "Successfully arrived at the end of a difficult enterprise" , "Having achieved one's objective" , "Definitely safe or successful" , "In a position to reach a goal without much further difficulty" .)