One doing very little in bridle-roads (5)
I believe the answer is:
idler
'one doing very little' is the definition.
(an idle or lazy person)
'in bridle-roads' is the wordplay.
'in' indicates a hidden word.
'IDLER' can be found hidden inside 'bridle roads'.
(Other definitions for idler that I've seen before include "stationary car perhaps?" , "Riled (anag)" , "Reluctant worker" , "One reluctant to work" , "Drone" .)