Unprincipled Frenchman after a spoken test (6)
I believe the answer is:
amoral
'unprincipled' is the definition.
(thesaurus)
'frenchman after a spoken test' is the wordplay.
'frenchman' becomes 'm' (abbreviation for Monsieur - like 'Mr').
'after' means one lot of letters go next to another.
'spoken test' becomes 'oral' (I've seen this before).
'm' put after 'a' is 'am'.
'am'+'oral'='AMORAL'
(Other definitions for amoral that I've seen before include "Without sense of right and wrong" , "Having no standards of right or wrong" , "Lacking spiritual values" , "Lacking any ethical standards" , "unconcerned about ethics" .)