Jim Morrison could make an entrance (4)
I believe the answer is:
door
'entrance' is the definition.
(I know that door is a type of entrance)
'jim morrison could make' is the wordplay.
I cannot really see how this works, but
'make' could be 'do' (do can mean to make or prepare) and 'do' is located in the answer.
The remaining letters 'or' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'an' acts as a link.
Can you help me to learn more?
(Other definitions for door that I've seen before include "Moveable structure at an entrance" , "Hinged barrier" , "Entrance way" , "Jim Morrison?" , "Usual entrance" .)