Elevator innovator (4)
I believe the answer is:
otis
'elevator innovator' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for otis that I've seen before include "Company providing lifts" , "lift company" , "Place of worship; side part of head" , "Miss -- Regrets, Cole Porter song" , "US inventor" .)