Taking the rest of the night (6)
I believe the answer is:
asleep
'taking the rest of the night' is the definition.
I can't tell whether this defines the answer.
'taking the rest' is the wordplay.
'taking' becomes 'a' (I can't explain this - if you can you should believe this answer much more).
'the rest' becomes 'sleep' ('sleep' can be a synonym of 'rest').
'a'+'sleep'='ASLEEP'
Can you help me to learn more?
(Other definitions for asleep that I've seen before include "Having nodded off" , "Napping" , "like a kipper" , "coiled up?" , "this fast?" .)