Idle chap is leading medic? (5)
I believe the answer is:
drone
This clue might be a double definition.
'idle chap' is the first definition.
'leading medic?' is the second definition.
The answer and definition can be both people as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'is' is the link.
(Other definitions for drone that I've seen before include "Unmanned aircraft" , "Someone who lives on the labour of others" , "Monotonous low sound" , "Aircraft operated by remote control" , "Idle person; bee" .)