Employed and entertained, but not in the morning (4)
I believe the answer is:
used
'employed' is the definition.
('use' can be a synonym of 'employ')
'entertained but not in the morning' is the wordplay.
'entertained' becomes 'amused' (synonyms).
'but not' indicates named letters should be taken away.
'in the morning' becomes 'am' (AM on a clock).
'amused' with 'am' removed is 'USED'.
'and' acts as a link.
(Other definitions for used that I've seen before include "with some traffic" , "Manipulated American editor" , "exhausted" , "Dues (anag.)" , "Pre-owned" .)