Wow! Lecturer seen in police line! (6)
I believe the answer is:
cordon
'police line' is the definition.
(I've seen this before)
'wow lecturer' is the wordplay.
'wow' becomes 'cor'.
'lecturer' becomes 'don' (don can mean an academic).
'cor'+'don'='CORDON'
'seen in' acts as a link.
(Other definitions for cordon that I've seen before include "In cooking, . . . . . . bleu is excellent" , "Chain (of police)" , "Line of police preventing passage" , "Line, of police say, to prevent passsage in and out" , "Ring of people guarding something" .)