Editor's written about body-builder (7)
I believe the answer is:
steroid
'body-builder' is the definition.
I can't judge whether this definition defines the answer.
'editor's written about' is the wordplay.
'written about' is an anagram indicator (letters moved about before being rewritten).
'editors' is an anagram of 'STEROID'.
Can you help me to learn more?
(Other definitions for steroid that I've seen before include "Controversial body-builder" , "Compound used as drug or performance enhancer" , "Type of drug, maybe anabolic" , "might be abused in gym" , "Compond such as many hormones and vitamins" .)