A leading publication? (5)
I believe the answer is:
guide
This could be a double definition.
'a leading' is the first definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'publication?' is the second definition.
(I know that guide is a type of enchiridion)
Can you help me to learn more?
(Other definitions for guide that I've seen before include "Navigate" , "Usher" , "Pilot" , "directory" , "conductor" .)