Sure, some get in if editor is rejected (8)
I believe the answer is:
definite
'sure' is the definition.
(I've seen this before)
'some get in if editor is rejected' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'is rejected' says the letters should be written in reverse.
'etinifed' is hidden in the letters of 'get in if editor'.
'etinifed' backwards is 'DEFINITE'.
(Other definitions for definite that I've seen before include "Certain; clearly stated" , "Sure, positive" , "'Certain, beyond doubt (8)'" , "Unmistakable" , "Explicit, positive" .)