Make up when actor is not acting? (6)
I believe the answer is:
offset
'make up' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for offset that I've seen before include "Something that compensates" , "Counteract to compensate" , "Counterbalance or compensate for" , "Compensate(d) for" , "Place at an angle to the main alignment" .)