Time waster hiding on bridle-road (5)
I believe the answer is:
idler
'time waster' is the definition.
(thesaurus)
'hiding on bridle-road' is the wordplay.
'hiding' indicates a hidden word.
'IDLER' can be found hidden inside 'on bridle road'.
(Other definitions for idler that I've seen before include "bad worker" , "Work-shy individual" , "Someone unemployed" , "One avoiding work" , "Good-for-nothing" .)