Doorman (7)
I believe the answer is:
bouncer
'doorman' is the definition.
(security guard stationed at a door)
This is all the clue.
(Other definitions for bouncer that I've seen before include "Nightclub security doorman" , "A heavy - ball, say" , "Club guard; short ball" , "A heavy - climbing cricket delivery" , "Chucker-out for nightclub" .)