Certain extract from bulletin, if edited the wrong way (8)
I believe the answer is:
definite
'certain' is the definition.
('definite' can be similar in meaning to 'certain')
'extract from bulletin if edited the wrong way' is the wordplay.
'extract from' indicates the answer is hidden within the clue (I've seen this in other clues).
'the wrong way' says the letters should be written in reverse.
'etinifed' can be found hidden inside 'bulletin if edited'.
'etinifed' backwards is 'DEFINITE'.
(Other definitions for definite that I've seen before include "The is the article" , "Sure, certain" , "Certain or explicit" , "Certain, decisive" , "Clearly decided" .)