Told editor to support book (7)
I believe the answer is:
ordered
'told' is the definition.
(given orders)
'editor to support book' is the wordplay.
I cannot really understand how this works, but
'editor' could be 'ed' (abbreviation) and 'ed' is present in the answer.
'book' could be 'order' (order book is a kind of book) and 'order' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ordered that I've seen before include "Demanded" , "Instructed" , "Gave instruction, commanded" , "Methodically arranged" , "Gave instructions" .)