Currently successful editor, one's told (8)
I believe the answer is:
informed
'told' is the definition.
(I've seen this before)
'currently successful editor one's' is the wordplay.
I cannot really see how this works, but
'successful' could be 'in' (similar in meaning) and 'in' is located in the answer.
'editor' could be 'ed' (abbreviation) and 'ed' is located in the answer.
The remaining letters 'form' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for informed that I've seen before include "Passed on knowledge" , "Told" , "Imparted knowledge" , "Knowledgeable or briefed" , "Gave knowledge to" .)