Train tracks (5)
'train tracks' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rails that I've seen before include "Wading birds - dysfunctional person has come off them" , "Tracks or barriers" , "Water birds" , "Train tracks" , "Barriers of horizontal bars and supports" .)
(Other definitions for railroad that I've seen before include "Bully" , "Push through unduly" , "Coerce (someone) into doing something" , "Unfairly force into decision - way for train" , "US term for train line" .)