Morning spent being entertained (6)
I believe the answer is:
amused
'being entertained' is the definition.
(synonyms)
'morning spent' is the wordplay.
'morning' becomes 'am' (as in 12:00 AM).
'spent' becomes 'used' (I've seen this in other clues).
'am'+'used'='AMUSED'
(Other definitions for amused that I've seen before include "Victoria reputedly wasn't" , "Queen Victoria wasn't!" , "was entertaining" , "Pleasantly occupied" , "Delighted" .)