To be precise, without the introduction, it's not fiction (6)
I believe the answer is:
actual
'to be precise' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for actual that I've seen before include "Real and current (6)" , "Real, not illusory" , "Existing in fact, current" , "Real and existing (6)" , "Real and concrete, not imaginary" .)