One may have got down for sleep (7,3)
I believe the answer is:
feather bed
'down for sleep' is the definition.
'feather bed' can be an answer for 'down' (thesaurus). I'm not certain of the 'for sleep' bit.
'one may have' is the wordplay.
'one may' becomes 'feather' (I am not sure about this - if you are sure you should believe this answer much more).
'have' becomes 'bed' (synonyms).
'feather'+'bed'='FEATHER-BED'
'got' acts as a link.
Can you help me to learn more?
(Other definitions for feather bed that I've seen before include "cushion" , "Provide incentive" , "Provide with extremely favourable conditions" , "Type of mattress" , "Pamper" .)