Objective, sent on special assignment? (8)
I believe the answer is:
detached
'objective' is the definition.
(similar in meaning)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for detached that I've seen before include "Not committed, objective" , "free of ties" , "Unprejudiced" , "isolated" , "Separate, disconnected" .)