A special bed, of course (5)
I believe the answer is:
ascot
'course' is the definition.
(I've seen this before)
'a special bed' is the wordplay.
'special' becomes 's' (common abbreviation as in Special Air Service).
'bed' becomes 'cot' (cot is a kind of bed).
'a'+'s'+'cot'='ASCOT'
'of' is the link.
(Other definitions for ascot that I've seen before include "Broad necktie" , "Fungus affecting wood" , "Racecourse with royal associations" , "English course" , "Society race meeting" .)