Rush in with a stepladder (5)
I believe the answer is:
haste
'rush' is the definition.
(I know that rush can be written as haste)
'in with a stepladder' is the wordplay.
'in' says the answer is hidden in the clue.
'HASTE' can be found hidden inside 'with a stepladder'.
(Other definitions for haste that I've seen before include "Rash speed" , "Hurry, urgency" , "Expeditiousness" , "Over-eager speed" , "Overly eager speed" .)