Moderate quits after being exposed (4)
I believe the answer is:
ease
'moderate' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for ease that I've seen before include "Assuage" , "Comfort and naturalness" , "Comfort or freedom from difficulty" , "Freedom from discomfort or anxiety" , "Free from pain" .)