Appear to be entertained by Chinese emperor (4)
I believe the answer is:
seem
'appear to be' is the definition.
(I've seen this before)
'entertained by chinese emperor' is the wordplay.
'entertained by' indicates the answer is hidden within the clue (the clue hosts or entertains the answer).
'SEEM' is hidden within 'chinese emperor'.
(Other definitions for seem that I've seen before include "Appear to the eye" , "Appear, look" , "Come across as" , "Appear, give impression of being" .)