Morning examination for the unprincipled (6)
I believe the answer is:
amoral
'the unprincipled' is the definition.
(I've seen this in another clue)
'morning examination' is the wordplay.
'morning' becomes 'am' (as in 12:00 AM).
'examination' becomes 'oral' (oral examination is a kind of examination).
'am'+'oral'='AMORAL'
'for' is the link.
(Other definitions for amoral that I've seen before include "Without sense of right and wrong" , "Lacking any ethical sense" , "Unconcerned with correctness" , "Lacking a sense of right and wrong" , "Lacking sense of decency" .)