It supports a light sleeper (3,3)
I believe the answer is:
day bed
'it supports a' is the definition.
The definition suggests a singular noun which matches the answer.
'light sleeper' is the wordplay.
'light' becomes 'day' (I've seen this in other clues).
'sleeper' becomes 'bed' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'day'+'bed'='DAY-BED'
Can you help me to learn more?
(Other definitions for day bed that I've seen before include "Hospital berth for short stay" , "Kind of couch or 1 dn" , "Kind of couch or sofa" .)