Suffered from exposure, but survived (9)
I believe the answer is:
weathered
'suffered' is the definition.
The definition and answer can be both related to change as well as being past participle verbs.
Perhaps you can see an association between them that I don't see?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for weathered that I've seen before include "Strengthened by being exposed to the elements" , "Worn by wind and rain" .)