Dismissed as openly gay (3)
I believe the answer is:
out
This clue is a double definition.
'dismissed' is the first definition.
(I've seen this before)
'openly gay' is the second definition.
(I've seen this before)
'as' is the link.
(Other definitions for out that I've seen before include "Old hat" , "Revealed; unconscious" , "Inaccurate - dismissed" , "in the shops" , "No longer imprisoned" .)