Unhappy actors covered by feathers (8)
I believe the answer is:
downcast
'unhappy' is the definition.
(thesaurus)
'actors covered by feathers' is the wordplay.
'actors' becomes 'cast' (I've seen this before).
'covered by' is a charade indicator (letters next to each other) (on top of in a down clue).
'feathers' becomes 'down' (down is a kind of feathers).
'cast' put after 'down' is 'DOWNCAST'.
(Other definitions for downcast that I've seen before include "blue" , "Melancholic" , "Depressed - looking at the floor?" , "Sad" , "Dejected and discouraged" .)