Stocking run (6)
I believe the answer is:
ladder
'stocking run' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ladder that I've seen before include "Household climbing device or tear in stocking" , "something that can send you in the opposite direction?" , "Unravel (as stocking)" , "A fire-fighter may use one" , "Set of rungs" .)