Foot part of the elevator (4)
I believe the answer is:
heel
'foot part' is the definition.
(I've seen this in another clue)
'of the elevator' is the wordplay.
'of' indicates the answer is hidden within the clue.
'HEEL' is hidden in the letters of 'the elevator'.
(Other definitions for heel that I've seen before include "Lean over; part of foot" , "Cad,bounder, blackguard" , "Slang scoundrel or rear of foot" , "Keel over" , "Despicable type" .)