Partly presumptuous, laid-back employer (4)
I believe the answer is:
user
'employer' is the definition.
(I've seen this before)
'partly presumptuous laid-back' is the wordplay.
'partly' indicates the answer is hidden within the clue.
'back' says the letters should be written in reverse.
'resu' is hidden within 'presumptuous laid'.
'resu' in reverse letter order is 'USER'.
(Other definitions for user that I've seen before include "one has to employ" , "Junkie's" , "One taking advantage" , "Druggie" , "Tech support caller?" .)