Naked after day in hotel is reserved (7)
I believe the answer is:
indrawn
'is reserved' is the definition.
('indrawn' can be similar in meaning to 'reserved')
'naked after day in hotel' is the wordplay.
'naked after day' becomes 'draw' (I am not sure about this - if you are sure you should believe this answer much more).
'in' is an insertion indicator.
'hotel' becomes 'inn' (inn is a kind of hotel).
'draw' placed inside 'inn' is 'INDRAWN'.
Can you help me to learn more?
(Other definitions for indrawn that I've seen before include "Taken in, like the breath" , "Breath so sharply" , "sucked in" , "Shy; inhaled" .)