Hairstyle rejected in Waldorf Astoria (4)
I believe the answer is:
afro
'hairstyle' is the definition.
(afro is a kind of hairstyle)
'rejected in waldorf astoria' is the wordplay.
'rejected' says the letters should be written backwards.
'in' indicates a hidden word.
'orfa' is hidden in the letters of 'waldorf astoria'.
'orfa' back-to-front is 'AFRO'.
(Other definitions for afro that I've seen before include "Retro hairdo" , "configuration of locks" , "shock treatment?" , "Hairdo of the 1960s and 70s" , "Big hairstyle" .)