Employing is funny, but not in the morning (5)
I believe the answer is:
using
'employing' is the definition.
(to employ is to use)
'funny but not in the morning' is the wordplay.
'funny' becomes 'amusing' (amusing means funny or entertaining).
'but not' indicates named letters should be taken away.
'in the morning' becomes 'am' (short for ante meridiem - before noon).
'amusing' with 'am' taken out is 'USING'.
'is' is the link.
(Other definitions for using that I've seen before include "practice" , "taking drugs" , "having recourse to" , "Exercising" , "Putting to a particular purpose" .)