Doorstop shape (5)
I believe the answer is:
wedge
'doorstop shape' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wedge that I've seen before include "Tapering object pushed into a gap - golf club" , "Tapered insert" , "It may cause division" , "Type of shoe" , "Tapered block" .)