Upright position (4)
I believe the answer is:
post
This clue is a double definition.
'upright' is the first definition.
(upright can mean a vertical post)
'position' is the second definition.
(post is a kind of position)
(Other definitions for post that I've seen before include "picket" , "Upright - letters" , "trading establishment" , "type of support" , "Send; job" .)