Attendant king on edge (6)
I believe the answer is:
verger
'attendant king on edge' is the definition.
I can't tell whether this defines the answer.
'attendant king on edge' is the wordplay.
'attendant king' becomes 'r' (abbreviation of Latin rex. I am not sure about the 'attendant' bit.).
'on' means one lot of letters go next to another.
'edge' becomes 'verge' (verge is a kind of edge).
'r' after 'verge' is 'VERGER'.
Can you help me to learn more?
(Other definitions for verger that I've seen before include "Church officer" , "Church official" , "Church caretaker and attendant" .)