Scout leader (5)
I believe the answer is:
tonto
'scout leader' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tonto that I've seen before include "Faithful companion" , "The Lone Ranger's companion" , "Western companion" , "Lone Ranger's scout" , "The Lone Ranger's sidekick" .)