Leading lawyer out to lunch? (7)
I believe the answer is:
barking
'leading' is the definition.
The answer and definition can be both to do with communicating as well as being present participle verbs.
Maybe there's a link between them I don't understand?
I can't explain the rest of the clue.
(Other definitions for barking that I've seen before include "Area of London - mad?" , "What Battersea resident may be doing" , "Mad - town forming a London borough with Dagenham" , "Completely mad" , "Mental" .)