Malign story about British lecturer (5)
I believe the answer is:
libel
'malign' is the definition.
(thesaurus)
'story about british lecturer' is the wordplay.
'story' becomes 'lie' (I've seen this before).
'about' means one lot of letters goes inside another.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'lecturer' becomes 'l'.
'lie' placed around 'b' is 'libe'.
'libe'+'l'='LIBEL'
(Other definitions for libel that I've seen before include "Offence" , "Crime of publishing false statement that damages reputation" , "Written defamation" , "Damaging publication" , "Calumny" .)