Ladder with its step shortened (3)
I believe the answer is:
run
'ladder' is the definition.
(both can mean a tear in tights)
'step shortened' is the wordplay.
'step' becomes 'rung' (I've seen this before).
'shortened' means to remove the last letter.
'rung' with its final letter removed is 'RUN'.
'with its' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
(Other definitions for run that I've seen before include "politician must do this to get elected" , "escape" , "Race; manage" , "Ladder - manage - sprint - flow" , "goal for England player?" .)