Trick somewhat mixed-up engineer (4)
I believe the answer is:
dupe
'trick' is the definition.
(I've seen this in another clue)
'somewhat mixed-up engineer' is the wordplay.
'somewhat' indicates the answer is hidden within the clue.
'DUPE' is hidden within 'mixed up engineer'.
(Other definitions for dupe that I've seen before include "Swindle" , "A cat's-paw" , "Put one over on, cod" , "Fool or hoax" , "One deceived, tricked" .)