Get ready to eat, perhaps (5)
I believe the answer is:
'get ready to eat' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for ripen that I've seen before include "Become ready to harvest" , "Become mature" , "Develop fully" , "Become ready to pick" , "Become ready for picking" .)