Elated with care, in a bed, though not thinking clearly (6-6)
I believe the answer is:
absent-minded
'not thinking clearly' is the definition.
'elated with care in a bed' is the wordplay.
'elated' becomes 'sent' (old-fashioned term meaning enraptured).
'with' means one lot of letters go next to another.
'care' becomes 'mind'.
'in' indicates putting letters inside.
'sent'+'mind'='sentmind'
'a'+'bed'='abed'
'sentmind' going inside 'abed' is 'ABSENT-MINDED'.
'though' acts as a link.
(Other definitions for absent-minded that I've seen before include "Scatty" , "Liable to inattentiveness" , "Prone to forgetfulness" , "Vague and forgetful" , "Given to woolgathering" .)